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2019-05-21ext4: actually request zeroing of inode table after growKirill Tkhai
commit 310a997fd74de778b9a4848a64be9cda9f18764a upstream. It is never possible, that number of block groups decreases, since only online grow is supported. But after a growing occured, we have to zero inode tables for just created new block groups. Fixes: 19c5246d2516 ("ext4: add new online resize interface") Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ext4: fix use-after-free race with debug_want_extra_isizeBarret Rhoden
commit 7bc04c5c2cc467c5b40f2b03ba08da174a0d5fa7 upstream. When remounting with debug_want_extra_isize, we were not performing the same checks that we do during a normal mount. That allowed us to set a value for s_want_extra_isize that reached outside the s_inode_size. Fixes: e2b911c53584 ("ext4: clean up feature test macros with predicate functions") Reported-by: syzbot+f584efa0ac7213c226b7@syzkaller.appspotmail.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Barret Rhoden <brho@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21bcache: never set KEY_PTRS of journal key to 0 in journal_reclaim()Coly Li
commit 1bee2addc0c8470c8aaa65ef0599eeae96dd88bc upstream. In journal_reclaim() ja->cur_idx of each cache will be update to reclaim available journal buckets. Variable 'int n' is used to count how many cache is successfully reclaimed, then n is set to c->journal.key by SET_KEY_PTRS(). Later in journal_write_unlocked(), a for_each_cache() loop will write the jset data onto each cache. The problem is, if all jouranl buckets on each cache is full, the following code in journal_reclaim(), 529 for_each_cache(ca, c, iter) { 530 struct journal_device *ja = &ca->journal; 531 unsigned int next = (ja->cur_idx + 1) % ca->sb.njournal_buckets; 532 533 /* No space available on this device */ 534 if (next == ja->discard_idx) 535 continue; 536 537 ja->cur_idx = next; 538 k->ptr[n++] = MAKE_PTR(0, 539 bucket_to_sector(c, ca->sb.d[ja->cur_idx]), 540 ca->sb.nr_this_dev); 541 } 542 543 bkey_init(k); 544 SET_KEY_PTRS(k, n); If there is no available bucket to reclaim, the if() condition at line 534 will always true, and n remains 0. Then at line 544, SET_KEY_PTRS() will set KEY_PTRS field of c->journal.key to 0. Setting KEY_PTRS field of c->journal.key to 0 is wrong. Because in journal_write_unlocked() the journal data is written in following loop, 649 for (i = 0; i < KEY_PTRS(k); i++) { 650-671 submit journal data to cache device 672 } If KEY_PTRS field is set to 0 in jouranl_reclaim(), the journal data won't be written to cache device here. If system crahed or rebooted before bkeys of the lost journal entries written into btree nodes, data corruption will be reported during bcache reload after rebooting the system. Indeed there is only one cache in a cache set, there is no need to set KEY_PTRS field in journal_reclaim() at all. But in order to keep the for_each_cache() logic consistent for now, this patch fixes the above problem by not setting 0 KEY_PTRS of journal key, if there is no bucket available to reclaim. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21bcache: fix a race between cache register and cacheset unregisterLiang Chen
commit a4b732a248d12cbdb46999daf0bf288c011335eb upstream. There is a race between cache device register and cache set unregister. For an already registered cache device, register_bcache will call bch_is_open to iterate through all cachesets and check every cache there. The race occurs if cache_set_free executes at the same time and clears the caches right before ca is dereferenced in bch_is_open_cache. To close the race, let's make sure the clean up work is protected by the bch_register_lock as well. This issue can be reproduced as follows, while true; do echo /dev/XXX> /sys/fs/bcache/register ; done& while true; do echo 1> /sys/block/XXX/bcache/set/unregister ; done & and results in the following oops, [ +0.000053] BUG: unable to handle kernel NULL pointer dereference at 0000000000000998 [ +0.000457] #PF error: [normal kernel read fault] [ +0.000464] PGD 800000003ca9d067 P4D 800000003ca9d067 PUD 3ca9c067 PMD 0 [ +0.000388] Oops: 0000 [#1] SMP PTI [ +0.000269] CPU: 1 PID: 3266 Comm: bash Not tainted 5.0.0+ #6 [ +0.000346] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.fc28 04/01/2014 [ +0.000472] RIP: 0010:register_bcache+0x1829/0x1990 [bcache] [ +0.000344] Code: b0 48 83 e8 50 48 81 fa e0 e1 10 c0 0f 84 a9 00 00 00 48 89 c6 48 89 ca 0f b7 ba 54 04 00 00 4c 8b 82 60 0c 00 00 85 ff 74 2f <49> 3b a8 98 09 00 00 74 4e 44 8d 47 ff 31 ff 49 c1 e0 03 eb 0d [ +0.000839] RSP: 0018:ffff92ee804cbd88 EFLAGS: 00010202 [ +0.000328] RAX: ffffffffc010e190 RBX: ffff918b5c6b5000 RCX: ffff918b7d8e0000 [ +0.000399] RDX: ffff918b7d8e0000 RSI: ffffffffc010e190 RDI: 0000000000000001 [ +0.000398] RBP: ffff918b7d318340 R08: 0000000000000000 R09: ffffffffb9bd2d7a [ +0.000385] R10: ffff918b7eb253c0 R11: ffffb95980f51200 R12: ffffffffc010e1a0 [ +0.000411] R13: fffffffffffffff2 R14: 000000000000000b R15: ffff918b7e232620 [ +0.000384] FS: 00007f955bec2740(0000) GS:ffff918b7eb00000(0000) knlGS:0000000000000000 [ +0.000420] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ +0.000801] CR2: 0000000000000998 CR3: 000000003cad6000 CR4: 00000000001406e0 [ +0.000837] Call Trace: [ +0.000682] ? _cond_resched+0x10/0x20 [ +0.000691] ? __kmalloc+0x131/0x1b0 [ +0.000710] kernfs_fop_write+0xfa/0x170 [ +0.000733] __vfs_write+0x2e/0x190 [ +0.000688] ? inode_security+0x10/0x30 [ +0.000698] ? selinux_file_permission+0xd2/0x120 [ +0.000752] ? security_file_permission+0x2b/0x100 [ +0.000753] vfs_write+0xa8/0x1a0 [ +0.000676] ksys_write+0x4d/0xb0 [ +0.000699] do_syscall_64+0x3a/0xf0 [ +0.000692] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Liang Chen <liangchen.linux@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21Btrfs: do not start a transaction at iterate_extent_inodes()Filipe Manana
commit bfc61c36260ca990937539cd648ede3cd749bc10 upstream. When finding out which inodes have references on a particular extent, done by backref.c:iterate_extent_inodes(), from the BTRFS_IOC_LOGICAL_INO (both v1 and v2) ioctl and from scrub we use the transaction join API to grab a reference on the currently running transaction, since in order to give accurate results we need to inspect the delayed references of the currently running transaction. However, if there is currently no running transaction, the join operation will create a new transaction. This is inefficient as the transaction will eventually be committed, doing unnecessary IO and introducing a potential point of failure that will lead to a transaction abort due to -ENOSPC, as recently reported [1]. That's because the join, creates the transaction but does not reserve any space, so when attempting to update the root item of the root passed to btrfs_join_transaction(), during the transaction commit, we can end up failling with -ENOSPC. Users of a join operation are supposed to actually do some filesystem changes and reserve space by some means, which is not the case of iterate_extent_inodes(), it is a read-only operation for all contextes from which it is called. The reported [1] -ENOSPC failure stack trace is the following: heisenberg kernel: ------------[ cut here ]------------ heisenberg kernel: BTRFS: Transaction aborted (error -28) heisenberg kernel: WARNING: CPU: 0 PID: 7137 at fs/btrfs/root-tree.c:136 btrfs_update_root+0x22b/0x320 [btrfs] (...) heisenberg kernel: CPU: 0 PID: 7137 Comm: btrfs-transacti Not tainted 4.19.0-4-amd64 #1 Debian 4.19.28-2 heisenberg kernel: Hardware name: FUJITSU LIFEBOOK U757/FJNB2A5, BIOS Version 1.21 03/19/2018 heisenberg kernel: RIP: 0010:btrfs_update_root+0x22b/0x320 [btrfs] (...) heisenberg kernel: RSP: 0018:ffffb5448828bd40 EFLAGS: 00010286 heisenberg kernel: RAX: 0000000000000000 RBX: ffff8ed56bccef50 RCX: 0000000000000006 heisenberg kernel: RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff8ed6bda166a0 heisenberg kernel: RBP: 00000000ffffffe4 R08: 00000000000003df R09: 0000000000000007 heisenberg kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff8ed63396a078 heisenberg kernel: R13: ffff8ed092d7c800 R14: ffff8ed64f5db028 R15: ffff8ed6bd03d068 heisenberg kernel: FS: 0000000000000000(0000) GS:ffff8ed6bda00000(0000) knlGS:0000000000000000 heisenberg kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 heisenberg kernel: CR2: 00007f46f75f8000 CR3: 0000000310a0a002 CR4: 00000000003606f0 heisenberg kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 heisenberg kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 heisenberg kernel: Call Trace: heisenberg kernel: commit_fs_roots+0x166/0x1d0 [btrfs] heisenberg kernel: ? _cond_resched+0x15/0x30 heisenberg kernel: ? btrfs_run_delayed_refs+0xac/0x180 [btrfs] heisenberg kernel: btrfs_commit_transaction+0x2bd/0x870 [btrfs] heisenberg kernel: ? start_transaction+0x9d/0x3f0 [btrfs] heisenberg kernel: transaction_kthread+0x147/0x180 [btrfs] heisenberg kernel: ? btrfs_cleanup_transaction+0x530/0x530 [btrfs] heisenberg kernel: kthread+0x112/0x130 heisenberg kernel: ? kthread_bind+0x30/0x30 heisenberg kernel: ret_from_fork+0x35/0x40 heisenberg kernel: ---[ end trace 05de912e30e012d9 ]--- So fix that by using the attach API, which does not create a transaction when there is currently no running transaction. [1] https://lore.kernel.org/linux-btrfs/b2a668d7124f1d3e410367f587926f622b3f03a4.camel@scientia.net/ Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21Btrfs: do not start a transaction during fiemapFilipe Manana
commit 03628cdbc64db6262e50d0357960a4e9562676a1 upstream. During fiemap, for regular extents (non inline) we need to check if they are shared and if they are, set the shared bit. Checking if an extent is shared requires checking the delayed references of the currently running transaction, since some reference might have not yet hit the extent tree and be only in the in-memory delayed references. However we were using a transaction join for this, which creates a new transaction when there is no transaction currently running. That means that two more potential failures can happen: creating the transaction and committing it. Further, if no write activity is currently happening in the system, and fiemap calls keep being done, we end up creating and committing transactions that do nothing. In some extreme cases this can result in the commit of the transaction created by fiemap to fail with ENOSPC when updating the root item of a subvolume tree because a join does not reserve any space, leading to a trace like the following: heisenberg kernel: ------------[ cut here ]------------ heisenberg kernel: BTRFS: Transaction aborted (error -28) heisenberg kernel: WARNING: CPU: 0 PID: 7137 at fs/btrfs/root-tree.c:136 btrfs_update_root+0x22b/0x320 [btrfs] (...) heisenberg kernel: CPU: 0 PID: 7137 Comm: btrfs-transacti Not tainted 4.19.0-4-amd64 #1 Debian 4.19.28-2 heisenberg kernel: Hardware name: FUJITSU LIFEBOOK U757/FJNB2A5, BIOS Version 1.21 03/19/2018 heisenberg kernel: RIP: 0010:btrfs_update_root+0x22b/0x320 [btrfs] (...) heisenberg kernel: RSP: 0018:ffffb5448828bd40 EFLAGS: 00010286 heisenberg kernel: RAX: 0000000000000000 RBX: ffff8ed56bccef50 RCX: 0000000000000006 heisenberg kernel: RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff8ed6bda166a0 heisenberg kernel: RBP: 00000000ffffffe4 R08: 00000000000003df R09: 0000000000000007 heisenberg kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff8ed63396a078 heisenberg kernel: R13: ffff8ed092d7c800 R14: ffff8ed64f5db028 R15: ffff8ed6bd03d068 heisenberg kernel: FS: 0000000000000000(0000) GS:ffff8ed6bda00000(0000) knlGS:0000000000000000 heisenberg kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 heisenberg kernel: CR2: 00007f46f75f8000 CR3: 0000000310a0a002 CR4: 00000000003606f0 heisenberg kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 heisenberg kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 heisenberg kernel: Call Trace: heisenberg kernel: commit_fs_roots+0x166/0x1d0 [btrfs] heisenberg kernel: ? _cond_resched+0x15/0x30 heisenberg kernel: ? btrfs_run_delayed_refs+0xac/0x180 [btrfs] heisenberg kernel: btrfs_commit_transaction+0x2bd/0x870 [btrfs] heisenberg kernel: ? start_transaction+0x9d/0x3f0 [btrfs] heisenberg kernel: transaction_kthread+0x147/0x180 [btrfs] heisenberg kernel: ? btrfs_cleanup_transaction+0x530/0x530 [btrfs] heisenberg kernel: kthread+0x112/0x130 heisenberg kernel: ? kthread_bind+0x30/0x30 heisenberg kernel: ret_from_fork+0x35/0x40 heisenberg kernel: ---[ end trace 05de912e30e012d9 ]--- Since fiemap (and btrfs_check_shared()) is a read-only operation, do not do a transaction join to avoid the overhead of creating a new transaction (if there is currently no running transaction) and introducing a potential point of failure when the new transaction gets committed, instead use a transaction attach to grab a handle for the currently running transaction if any. Reported-by: Christoph Anton Mitterer <calestyo@scientia.net> Link: https://lore.kernel.org/linux-btrfs/b2a668d7124f1d3e410367f587926f622b3f03a4.camel@scientia.net/ Fixes: afce772e87c36c ("btrfs: fix check_shared for fiemap ioctl") CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ext4: avoid drop reference to iloc.bh twicePan Bian
commit 8c380ab4b7b59c0c602743810be1b712514eaebc upstream. The reference to iloc.bh has been dropped in ext4_mark_iloc_dirty. However, the reference is dropped again if error occurs during ext4_handle_dirty_metadata, which may result in use-after-free bugs. Fixes: fb265c9cb49e("ext4: add ext4_sb_bread() to disambiguate ENOMEM cases") Signed-off-by: Pan Bian <bianpan2016@163.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ext4: ignore e_value_offs for xattrs with value-in-ea-inodeTheodore Ts'o
commit e5d01196c0428a206f307e9ee5f6842964098ff0 upstream. In other places in fs/ext4/xattr.c, if e_value_inum is non-zero, the code ignores the value in e_value_offs. The e_value_offs *should* be zero, but we shouldn't depend upon it, since it might not be true in a corrupted/fuzzed file system. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202897 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202877 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ext4: make sanity check in mballoc more strictJan Kara
commit 31562b954b60f02acb91b7349dc6432d3f8c3c5f upstream. The sanity check in mb_find_extent() only checked that returned extent does not extend past blocksize * 8, however it should not extend past EXT4_CLUSTERS_PER_GROUP(sb). This can happen when clusters_per_group < blocksize * 8 and the tail of the bitmap is not properly filled by 1s which happened e.g. when ancient kernels have grown the filesystem. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21jbd2: check superblock mapped prior to committingJiufei Xue
commit 742b06b5628f2cd23cb51a034cb54dc33c6162c5 upstream. We hit a BUG at fs/buffer.c:3057 if we detached the nbd device before unmounting ext4 filesystem. The typical chain of events leading to the BUG: jbd2_write_superblock submit_bh submit_bh_wbc BUG_ON(!buffer_mapped(bh)); The block device is removed and all the pages are invalidated. JBD2 was trying to write journal superblock to the block device which is no longer present. Fix this by checking the journal superblock's buffer head prior to submitting. Reported-by: Eric Ren <renzhen@linux.alibaba.com> Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21tty/vt: fix write/write race in ioctl(KDSKBSENT) handlerSergei Trofimovich
commit 46ca3f735f345c9d87383dd3a09fa5d43870770e upstream. The bug manifests as an attempt to access deallocated memory: BUG: unable to handle kernel paging request at ffff9c8735448000 #PF error: [PROT] [WRITE] PGD 288a05067 P4D 288a05067 PUD 288a07067 PMD 7f60c2063 PTE 80000007f5448161 Oops: 0003 [#1] PREEMPT SMP CPU: 6 PID: 388 Comm: loadkeys Tainted: G C 5.0.0-rc6-00153-g5ded5871030e #91 Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./H77M-D3H, BIOS F12 11/14/2013 RIP: 0010:__memmove+0x81/0x1a0 Code: 4c 89 4f 10 4c 89 47 18 48 8d 7f 20 73 d4 48 83 c2 20 e9 a2 00 00 00 66 90 48 89 d1 4c 8b 5c 16 f8 4c 8d 54 17 f8 48 c1 e9 03 <f3> 48 a5 4d 89 1a e9 0c 01 00 00 0f 1f 40 00 48 89 d1 4c 8b 1e 49 RSP: 0018:ffffa1b9002d7d08 EFLAGS: 00010203 RAX: ffff9c873541af43 RBX: ffff9c873541af43 RCX: 00000c6f105cd6bf RDX: 0000637882e986b6 RSI: ffff9c8735447ffb RDI: ffff9c8735447ffb RBP: ffff9c8739cd3800 R08: ffff9c873b802f00 R09: 00000000fffff73b R10: ffffffffb82b35f1 R11: 00505b1b004d5b1b R12: 0000000000000000 R13: ffff9c873541af3d R14: 000000000000000b R15: 000000000000000c FS: 00007f450c390580(0000) GS:ffff9c873f180000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff9c8735448000 CR3: 00000007e213c002 CR4: 00000000000606e0 Call Trace: vt_do_kdgkb_ioctl+0x34d/0x440 vt_ioctl+0xba3/0x1190 ? __bpf_prog_run32+0x39/0x60 ? mem_cgroup_commit_charge+0x7b/0x4e0 tty_ioctl+0x23f/0x920 ? preempt_count_sub+0x98/0xe0 ? __seccomp_filter+0x67/0x600 do_vfs_ioctl+0xa2/0x6a0 ? syscall_trace_enter+0x192/0x2d0 ksys_ioctl+0x3a/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x54/0xe0 entry_SYSCALL_64_after_hwframe+0x49/0xbe The bug manifests on systemd systems with multiple vtcon devices: # cat /sys/devices/virtual/vtconsole/vtcon0/name (S) dummy device # cat /sys/devices/virtual/vtconsole/vtcon1/name (M) frame buffer device There systemd runs 'loadkeys' tool in tapallel for each vtcon instance. This causes two parallel ioctl(KDSKBSENT) calls to race into adding the same entry into 'func_table' array at: drivers/tty/vt/keyboard.c:vt_do_kdgkb_ioctl() The function has no locking around writes to 'func_table'. The simplest reproducer is to have initrams with the following init on a 8-CPU machine x86_64: #!/bin/sh loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & wait The change adds lock on write path only. Reads are still racy. CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CC: Jiri Slaby <jslaby@suse.com> Link: https://lkml.org/lkml/2019/2/17/256 Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21tty: vt.c: Fix TIOCL_BLANKSCREEN console blanking if blankinterval == 0Yifeng Li
commit 75ddbc1fb11efac87b611d48e9802f6fe2bb2163 upstream. Previously, in the userspace, it was possible to use the "setterm" command from util-linux to blank the VT console by default, using the following command. According to the man page, > The force option keeps the screen blank even if a key is pressed. It was implemented by calling TIOCL_BLANKSCREEN. case BLANKSCREEN: ioctlarg = TIOCL_BLANKSCREEN; if (ioctl(STDIN_FILENO, TIOCLINUX, &ioctlarg)) warn(_("cannot force blank")); break; However, after Linux 4.12, this command ceased to work anymore, which is unexpected. By inspecting the kernel source, it shows that the issue was triggered by the side-effect from commit a4199f5eb809 ("tty: Disable default console blanking interval"). The console blanking is implemented by function do_blank_screen() in vt.c: "blank_state" will be initialized to "blank_normal_wait" in con_init() if AND ONLY IF ("blankinterval" > 0). If "blankinterval" is 0, "blank_state" will be "blank_off" (== 0), and a call to do_blank_screen() will always abort, even if a forced blanking is required from the user by calling TIOCL_BLANKSCREEN, the console won't be blanked. This behavior is unexpected from a user's point-of-view, since it's not mentioned in any documentation. The setterm man page suggests it will always work, and the kernel comments in uapi/linux/tiocl.h says > /* keep screen blank even if a key is pressed */ > #define TIOCL_BLANKSCREEN 14 To fix it, we simply remove the "blank_state != blank_off" check, as pointed out by Nicolas Pitre, this check doesn't logically make sense and it's safe to remove. Suggested-by: Nicolas Pitre <nicolas.pitre@linaro.org> Fixes: a4199f5eb809 ("tty: Disable default console blanking interval") Signed-off-by: Yifeng Li <tomli@tomli.me> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21mtd: spi-nor: intel-spi: Avoid crossing 4K address boundary on read/writeAlexander Sverdlin
commit 2b75ebeea6f4937d4d05ec4982c471cef9a29b7f upstream. It was observed that reads crossing 4K address boundary are failing. This limitation is mentioned in Intel documents: Intel(R) 9 Series Chipset Family Platform Controller Hub (PCH) Datasheet: "5.26.3 Flash Access Program Register Access: * Program Register Accesses are not allowed to cross a 4 KB boundary..." Enhanced Serial Peripheral Interface (eSPI) Interface Base Specification (for Client and Server Platforms): "5.1.4 Address For other memory transactions, the address may start or end at any byte boundary. However, the address and payload length combination must not cross the naturally aligned address boundary of the corresponding Maximum Payload Size. It must not cross a 4 KB address boundary." Avoid this by splitting an operation crossing the boundary into two operations. Fixes: 8afda8b26d01 ("spi-nor: Add support for Intel SPI serial flash controller") Cc: stable@vger.kernel.org Reported-by: Romain Porte <romain.porte@nokia.com> Tested-by: Pascal Fabreges <pascal.fabreges@nokia.com> Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21mfd: max77620: Fix swapped FPS_PERIOD_MAX_US valuesDmitry Osipenko
commit ea611d1cc180fbb56982c83cd5142a2b34881f5c upstream. The FPS_PERIOD_MAX_US definitions are swapped for MAX20024 and MAX77620, fix it. Cc: stable <stable@vger.kernel.org> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21mfd: da9063: Fix OTP control register names to match datasheets for DA9063/63LSteve Twiss
commit 6b4814a9451add06d457e198be418bf6a3e6a990 upstream. Mismatch between what is found in the Datasheets for DA9063 and DA9063L provided by Dialog Semiconductor, and the register names provided in the MFD registers file. The changes are for the OTP (one-time-programming) control registers. The two naming errors are OPT instead of OTP, and COUNT instead of CONT (i.e. control). Cc: Stable <stable@vger.kernel.org> Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21userfaultfd: use RCU to free the task struct when fork failsAndrea Arcangeli
commit c3f3ce049f7d97cc7ec9c01cb51d9ec74e0f37c2 upstream. The task structure is freed while get_mem_cgroup_from_mm() holds rcu_read_lock() and dereferences mm->owner. get_mem_cgroup_from_mm() failing fork() ---- --- task = mm->owner mm->owner = NULL; free(task) if (task) *task; /* use after free */ The fix consists in freeing the task with RCU also in the fork failure case, exactly like it always happens for the regular exit(2) path. That is enough to make the rcu_read_lock hold in get_mem_cgroup_from_mm() (left side above) effective to avoid a use after free when dereferencing the task structure. An alternate possible fix would be to defer the delivery of the userfaultfd contexts to the monitor until after fork() is guaranteed to succeed. Such a change would require more changes because it would create a strict ordering dependency where the uffd methods would need to be called beyond the last potentially failing branch in order to be safe. This solution as opposed only adds the dependency to common code to set mm->owner to NULL and to free the task struct that was pointed by mm->owner with RCU, if fork ends up failing. The userfaultfd methods can still be called anywhere during the fork runtime and the monitor will keep discarding orphaned "mm" coming from failed forks in userland. This race condition couldn't trigger if CONFIG_MEMCG was set =n at build time. [aarcange@redhat.com: improve changelog, reduce #ifdefs per Michal] Link: http://lkml.kernel.org/r/20190429035752.4508-1-aarcange@redhat.com Link: http://lkml.kernel.org/r/20190325225636.11635-2-aarcange@redhat.com Fixes: 893e26e61d04 ("userfaultfd: non-cooperative: Add fork() event") Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Tested-by: zhong jiang <zhongjiang@huawei.com> Reported-by: syzbot+cbb52e396df3e565ab02@syzkaller.appspotmail.com Cc: Oleg Nesterov <oleg@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Peter Xu <peterx@redhat.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: zhong jiang <zhongjiang@huawei.com> Cc: syzbot+cbb52e396df3e565ab02@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ocfs2: fix ocfs2 read inode data panic in ocfs2_igetShuning Zhang
commit e091eab028f9253eac5c04f9141bbc9d170acab3 upstream. In some cases, ocfs2_iget() reads the data of inode, which has been deleted for some reason. That will make the system panic. So We should judge whether this inode has been deleted, and tell the caller that the inode is a bad inode. For example, the ocfs2 is used as the backed of nfs, and the client is nfsv3. This issue can be reproduced by the following steps. on the nfs server side, ..../patha/pathb Step 1: The process A was scheduled before calling the function fh_verify. Step 2: The process B is removing the 'pathb', and just completed the call to function dput. Then the dentry of 'pathb' has been deleted from the dcache, and all ancestors have been deleted also. The relationship of dentry and inode was deleted through the function hlist_del_init. The following is the call stack. dentry_iput->hlist_del_init(&dentry->d_u.d_alias) At this time, the inode is still in the dcache. Step 3: The process A call the function ocfs2_get_dentry, which get the inode from dcache. Then the refcount of inode is 1. The following is the call stack. nfsd3_proc_getacl->fh_verify->exportfs_decode_fh->fh_to_dentry(ocfs2_get_dentry) Step 4: Dirty pages are flushed by bdi threads. So the inode of 'patha' is evicted, and this directory was deleted. But the inode of 'pathb' can't be evicted, because the refcount of the inode was 1. Step 5: The process A keep running, and call the function reconnect_path(in exportfs_decode_fh), which call function ocfs2_get_parent of ocfs2. Get the block number of parent directory(patha) by the name of ... Then read the data from disk by the block number. But this inode has been deleted, so the system panic. Process A Process B 1. in nfsd3_proc_getacl | 2. | dput 3. fh_to_dentry(ocfs2_get_dentry) | 4. bdi flush dirty cache | 5. ocfs2_iget | [283465.542049] OCFS2: ERROR (device sdp): ocfs2_validate_inode_block: Invalid dinode #580640: OCFS2_VALID_FL not set [283465.545490] Kernel panic - not syncing: OCFS2: (device sdp): panic forced after error [283465.546889] CPU: 5 PID: 12416 Comm: nfsd Tainted: G W 4.1.12-124.18.6.el6uek.bug28762940v3.x86_64 #2 [283465.548382] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/21/2015 [283465.549657] 0000000000000000 ffff8800a56fb7b8 ffffffff816e839c ffffffffa0514758 [283465.550392] 000000000008dc20 ffff8800a56fb838 ffffffff816e62d3 0000000000000008 [283465.551056] ffff880000000010 ffff8800a56fb848 ffff8800a56fb7e8 ffff88005df9f000 [283465.551710] Call Trace: [283465.552516] [<ffffffff816e839c>] dump_stack+0x63/0x81 [283465.553291] [<ffffffff816e62d3>] panic+0xcb/0x21b [283465.554037] [<ffffffffa04e66b0>] ocfs2_handle_error+0xf0/0xf0 [ocfs2] [283465.554882] [<ffffffffa04e7737>] __ocfs2_error+0x67/0x70 [ocfs2] [283465.555768] [<ffffffffa049c0f9>] ocfs2_validate_inode_block+0x229/0x230 [ocfs2] [283465.556683] [<ffffffffa047bcbc>] ocfs2_read_blocks+0x46c/0x7b0 [ocfs2] [283465.557408] [<ffffffffa049bed0>] ? ocfs2_inode_cache_io_unlock+0x20/0x20 [ocfs2] [283465.557973] [<ffffffffa049f0eb>] ocfs2_read_inode_block_full+0x3b/0x60 [ocfs2] [283465.558525] [<ffffffffa049f5ba>] ocfs2_iget+0x4aa/0x880 [ocfs2] [283465.559082] [<ffffffffa049146e>] ocfs2_get_parent+0x9e/0x220 [ocfs2] [283465.559622] [<ffffffff81297c05>] reconnect_path+0xb5/0x300 [283465.560156] [<ffffffff81297f46>] exportfs_decode_fh+0xf6/0x2b0 [283465.560708] [<ffffffffa062faf0>] ? nfsd_proc_getattr+0xa0/0xa0 [nfsd] [283465.561262] [<ffffffff810a8196>] ? prepare_creds+0x26/0x110 [283465.561932] [<ffffffffa0630860>] fh_verify+0x350/0x660 [nfsd] [283465.562862] [<ffffffffa0637804>] ? nfsd_cache_lookup+0x44/0x630 [nfsd] [283465.563697] [<ffffffffa063a8b9>] nfsd3_proc_getattr+0x69/0xf0 [nfsd] [283465.564510] [<ffffffffa062cf60>] nfsd_dispatch+0xe0/0x290 [nfsd] [283465.565358] [<ffffffffa05eb892>] ? svc_tcp_adjust_wspace+0x12/0x30 [sunrpc] [283465.566272] [<ffffffffa05ea652>] svc_process_common+0x412/0x6a0 [sunrpc] [283465.567155] [<ffffffffa05eaa03>] svc_process+0x123/0x210 [sunrpc] [283465.568020] [<ffffffffa062c90f>] nfsd+0xff/0x170 [nfsd] [283465.568962] [<ffffffffa062c810>] ? nfsd_destroy+0x80/0x80 [nfsd] [283465.570112] [<ffffffff810a622b>] kthread+0xcb/0xf0 [283465.571099] [<ffffffff810a6160>] ? kthread_create_on_node+0x180/0x180 [283465.572114] [<ffffffff816f11b8>] ret_from_fork+0x58/0x90 [283465.573156] [<ffffffff810a6160>] ? kthread_create_on_node+0x180/0x180 Link: http://lkml.kernel.org/r/1554185919-3010-1-git-send-email-sunny.s.zhang@oracle.com Signed-off-by: Shuning Zhang <sunny.s.zhang@oracle.com> Reviewed-by: Joseph Qi <jiangqi903@gmail.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: piaojun <piaojun@huawei.com> Cc: "Gang He" <ghe@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21mm/mincore.c: make mincore() more conservativeJiri Kosina
commit 134fca9063ad4851de767d1768180e5dede9a881 upstream. The semantics of what mincore() considers to be resident is not completely clear, but Linux has always (since 2.3.52, which is when mincore() was initially done) treated it as "page is available in page cache". That's potentially a problem, as that [in]directly exposes meta-information about pagecache / memory mapping state even about memory not strictly belonging to the process executing the syscall, opening possibilities for sidechannel attacks. Change the semantics of mincore() so that it only reveals pagecache information for non-anonymous mappings that belog to files that the calling process could (if it tried to) successfully open for writing; otherwise we'd be including shared non-exclusive mappings, which - is the sidechannel - is not the usecase for mincore(), as that's primarily used for data, not (shared) text [jkosina@suse.cz: v2] Link: http://lkml.kernel.org/r/20190312141708.6652-2-vbabka@suse.cz [mhocko@suse.com: restructure can_do_mincore() conditions] Link: http://lkml.kernel.org/r/nycvar.YFH.7.76.1903062342020.19912@cbobk.fhfr.pm Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Josh Snyder <joshs@netflix.com> Acked-by: Michal Hocko <mhocko@suse.com> Originally-by: Linus Torvalds <torvalds@linux-foundation.org> Originally-by: Dominique Martinet <asmadeus@codewreck.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Chinner <david@fromorbit.com> Cc: Kevin Easton <kevin@guarana.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Cyril Hrubis <chrubis@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Daniel Gruss <daniel@gruss.cc> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21bpf, arm64: remove prefetch insn in xadd mappingDaniel Borkmann
commit 8968c67a82ab7501bc3b9439c3624a49b42fe54c upstream. Prefetch-with-intent-to-write is currently part of the XADD mapping in the AArch64 JIT and follows the kernel's implementation of atomic_add. This may interfere with other threads executing the LDXR/STXR loop, leading to potential starvation and fairness issues. Drop the optional prefetch instruction. Fixes: 85f68fe89832 ("bpf, arm64: implement jiting of BPF_XADD") Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ASoC: RT5677-SPI: Disable 16Bit SPI TransfersCurtis Malainey
commit a46eb523220e242affb9a6bc9bb8efc05f4f7459 upstream. The current algorithm allows 3 types of transfers, 16bit, 32bit and burst. According to Realtek, 16bit transfers have a special restriction in that it is restricted to the memory region of 0x18020000 ~ 0x18021000. This region is the memory location of the I2C registers. The current algorithm does not uphold this restriction and therefore fails to complete writes. Since this has been broken for some time it likely no one is using it. Better to simply disable the 16 bit writes. This will allow users to properly load firmware over SPI without data corruption. Signed-off-by: Curtis Malainey <cujomalainey@chromium.org> Reviewed-by: Ben Zhang <benzh@chromium.org> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ASoC: max98090: Fix restore of DAPM MuxesJon Hunter
commit ecb2795c08bc825ebd604997e5be440b060c5b18 upstream. The max98090 driver defines 3 DAPM muxes; one for the right line output (LINMOD Mux), one for the left headphone mixer source (MIXHPLSEL Mux) and one for the right headphone mixer source (MIXHPRSEL Mux). The same bit is used for the mux as well as the DAPM enable, and although the mux can be correctly configured, after playback has completed, the mux will be reset during the disable phase. This is preventing the state of these muxes from being saved and restored correctly on system reboot. Fix this by marking these muxes as SND_SOC_NOPM. Note this has been verified this on the Tegra124 Nyan Big which features the MAX98090 codec. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ALSA: hda/realtek - EAPD turn on laterKailang Yang
commit 607ca3bd220f4022e6f5356026b19dafc363863a upstream. Let EAPD turn on after set pin output. [ NOTE: This change is supposed to reduce the possible click noises at (runtime) PM resume. The functionality should be same (i.e. the verbs are executed correctly) no matter which order is, so this should be safe to apply for all codecs -- tiwai ] Signed-off-by: Kailang Yang <kailang@realtek.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ALSA: hda/hdmi - Consider eld_valid when reporting jack eventHui Wang
commit 7f641e26a6df9269cb25dd7a4b0a91d6586ed441 upstream. On the machines with AMD GPU or Nvidia GPU, we often meet this issue: after s3, there are 4 HDMI/DP audio devices in the gnome-sound-setting even there is no any monitors plugged. When this problem happens, we check the /proc/asound/cardX/eld#N.M, we will find the monitor_present=1, eld_valid=0. The root cause is BIOS or GPU driver makes the PRESENCE valid even no monitor plugged, and of course the driver will not get the valid eld_data subsequently. In this situation, we should not report the jack_plugged event, to do so, let us change the function hdmi_present_sense_via_verbs(). In this function, it reads the pin_sense via snd_hda_pin_sense(), after calling this function, the jack_dirty is 0, and before exiting via_verbs(), we change the shadow pin_sense according to both monitor_present and eld_valid, then in the snd_hda_jack_report_sync(), since the jack_dirty is still 0, it will report jack event according to this modified shadow pin_sense. After this change, the driver will not report Jack_is_plugged event through hdmi_present_sense_via_verbs() if monitor_present is 1 and eld_valid is 0. Signed-off-by: Hui Wang <hui.wang@canonical.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ALSA: hda/hdmi - Read the pin sense from register when repollingHui Wang
commit 8c2e6728c2bf95765b724e07d0278ae97cd1ee0d upstream. The driver will check the monitor presence when resuming from suspend, starting poll or interrupt triggers. In these 3 situations, the jack_dirty will be set to 1 first, then the hda_jack.c reads the pin_sense from register, after reading the register, the jack_dirty will be set to 0. But hdmi_repoll_work() is enabled in these 3 situations, It will read the pin_sense a couple of times subsequently, since the jack_dirty is 0 now, It does not read the register anymore, instead it uses the shadow pin_sense which is read at the first time. It is meaningless to check the shadow pin_sense a couple of times, we need to read the register to check the real plugging state, so we set the jack_dirty to 1 in the hdmi_repoll_work(). Signed-off-by: Hui Wang <hui.wang@canonical.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ALSA: usb-audio: Fix a memory leak bugWenwen Wang
commit cb5173594d50c72b7bfa14113dfc5084b4d2f726 upstream. In parse_audio_selector_unit(), the string array 'namelist' is allocated through kmalloc_array(), and each string pointer in this array, i.e., 'namelist[]', is allocated through kmalloc() in the following for loop. Then, a control instance 'kctl' is created by invoking snd_ctl_new1(). If an error occurs during the creation process, the string array 'namelist', including all string pointers in the array 'namelist[]', should be freed, before the error code ENOMEM is returned. However, the current code does not free 'namelist[]', resulting in memory leaks. To fix the above issue, free all string pointers 'namelist[]' in a loop. Signed-off-by: Wenwen Wang <wang6495@umn.edu> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21crypto: arm/aes-neonbs - don't access already-freed walk.ivEric Biggers
commit 767f015ea0b7ab9d60432ff6cd06b664fd71f50f upstream. If the user-provided IV needs to be aligned to the algorithm's alignmask, then skcipher_walk_virt() copies the IV into a new aligned buffer walk.iv. But skcipher_walk_virt() can fail afterwards, and then if the caller unconditionally accesses walk.iv, it's a use-after-free. arm32 xts-aes-neonbs doesn't set an alignmask, so currently it isn't affected by this despite unconditionally accessing walk.iv. However this is more subtle than desired, and it was actually broken prior to the alignmask being removed by commit cc477bf64573 ("crypto: arm/aes - replace bit-sliced OpenSSL NEON code"). Thus, update xts-aes-neonbs to start checking the return value of skcipher_walk_virt(). Fixes: e4e7f10bfc40 ("ARM: add support for bit sliced AES using NEON instructions") Cc: <stable@vger.kernel.org> # v3.13+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21crypto: rockchip - update IV buffer to contain the next IVZhang Zhijie
commit f0cfd57b43fec65761ca61d3892b983a71515f23 upstream. The Kernel Crypto API request output the next IV data to IV buffer for CBC implementation. So the last block data of ciphertext should be copid into assigned IV buffer. Reported-by: Eric Biggers <ebiggers@google.com> Fixes: 433cd2c617bf ("crypto: rockchip - add crypto driver for rk3288") Cc: <stable@vger.kernel.org> # v4.5+ Signed-off-by: Zhang Zhijie <zhangzj@rock-chips.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21crypto: gcm - fix incompatibility between "gcm" and "gcm_base"Eric Biggers
commit f699594d436960160f6d5ba84ed4a222f20d11cd upstream. GCM instances can be created by either the "gcm" template, which only allows choosing the block cipher, e.g. "gcm(aes)"; or by "gcm_base", which allows choosing the ctr and ghash implementations, e.g. "gcm_base(ctr(aes-generic),ghash-generic)". However, a "gcm_base" instance prevents a "gcm" instance from being registered using the same implementations. Nor will the instance be found by lookups of "gcm". This can be used as a denial of service. Moreover, "gcm_base" instances are never tested by the crypto self-tests, even if there are compatible "gcm" tests. The root cause of these problems is that instances of the two templates use different cra_names. Therefore, fix these problems by making "gcm_base" instances set the same cra_name as "gcm" instances, e.g. "gcm(aes)" instead of "gcm_base(ctr(aes-generic),ghash-generic)". This requires extracting the block cipher name from the name of the ctr algorithm. It also requires starting to verify that the algorithms are really ctr and ghash, not something else entirely. But it would be bizarre if anyone were actually using non-gcm-compatible algorithms with gcm_base, so this shouldn't break anyone in practice. Fixes: d00aa19b507b ("[CRYPTO] gcm: Allow block cipher parameter") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21crypto: x86/crct10dif-pcl - fix use via crypto_shash_digest()Eric Biggers
commit dec3d0b1071a0f3194e66a83d26ecf4aa8c5910e upstream. The ->digest() method of crct10dif-pclmul reads the current CRC value from the shash_desc context. But this value is uninitialized, causing crypto_shash_digest() to compute the wrong result. Fix it. Probably this wasn't noticed before because lib/crc-t10dif.c only uses crypto_shash_update(), not crypto_shash_digest(). Likewise, crypto_shash_digest() is not yet tested by the crypto self-tests because those only test the ahash API which only uses shash init/update/final. Fixes: 0b95a7f85718 ("crypto: crct10dif - Glue code to cast accelerated CRCT10DIF assembly as a crypto transform") Cc: <stable@vger.kernel.org> # v3.11+ Cc: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21crypto: crct10dif-generic - fix use via crypto_shash_digest()Eric Biggers
commit 307508d1072979f4435416f87936f87eaeb82054 upstream. The ->digest() method of crct10dif-generic reads the current CRC value from the shash_desc context. But this value is uninitialized, causing crypto_shash_digest() to compute the wrong result. Fix it. Probably this wasn't noticed before because lib/crc-t10dif.c only uses crypto_shash_update(), not crypto_shash_digest(). Likewise, crypto_shash_digest() is not yet tested by the crypto self-tests because those only test the ahash API which only uses shash init/update/final. This bug was detected by my patches that improve testmgr to fuzz algorithms against their generic implementation. Fixes: 2d31e518a428 ("crypto: crct10dif - Wrap crc_t10dif function all to use crypto transform framework") Cc: <stable@vger.kernel.org> # v3.11+ Cc: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21crypto: skcipher - don't WARN on unprocessed data after slow walk stepEric Biggers
commit dcaca01a42cc2c425154a13412b4124293a6e11e upstream. skcipher_walk_done() assumes it's a bug if, after the "slow" path is executed where the next chunk of data is processed via a bounce buffer, the algorithm says it didn't process all bytes. Thus it WARNs on this. However, this can happen legitimately when the message needs to be evenly divisible into "blocks" but isn't, and the algorithm has a 'walksize' greater than the block size. For example, ecb-aes-neonbs sets 'walksize' to 128 bytes and only supports messages evenly divisible into 16-byte blocks. If, say, 17 message bytes remain but they straddle scatterlist elements, the skcipher_walk code will take the "slow" path and pass the algorithm all 17 bytes in the bounce buffer. But the algorithm will only be able to process 16 bytes, triggering the WARN. Fix this by just removing the WARN_ON(). Returning -EINVAL, as the code already does, is the right behavior. This bug was detected by my patches that improve testmgr to fuzz algorithms against their generic implementation. Fixes: b286d8b1a690 ("crypto: skcipher - Add skcipher walk interface") Cc: <stable@vger.kernel.org> # v4.10+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21crypto: vmx - fix copy-paste error in CTR modeDaniel Axtens
commit dcf7b48212c0fab7df69e84fab22d6cb7c8c0fb9 upstream. The original assembly imported from OpenSSL has two copy-paste errors in handling CTR mode. When dealing with a 2 or 3 block tail, the code branches to the CBC decryption exit path, rather than to the CTR exit path. This leads to corruption of the IV, which leads to subsequent blocks being corrupted. This can be detected with libkcapi test suite, which is available at https://github.com/smuellerDD/libkcapi Reported-by: Ondrej Mosnáček <omosnacek@gmail.com> Fixes: 5c380d623ed3 ("crypto: vmx - Add support for VMS instructions by ASM") Cc: stable@vger.kernel.org Signed-off-by: Daniel Axtens <dja@axtens.net> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Ondrej Mosnacek <omosnacek@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21crypto: chacha20poly1305 - set cra_name correctlyEric Biggers
commit 5e27f38f1f3f45a0c938299c3a34a2d2db77165a upstream. If the rfc7539 template is instantiated with specific implementations, e.g. "rfc7539(chacha20-generic,poly1305-generic)" rather than "rfc7539(chacha20,poly1305)", then the implementation names end up included in the instance's cra_name. This is incorrect because it then prevents all users from allocating "rfc7539(chacha20,poly1305)", if the highest priority implementations of chacha20 and poly1305 were selected. Also, the self-tests aren't run on an instance allocated in this way. Fix it by setting the instance's cra_name from the underlying algorithms' actual cra_names, rather than from the requested names. This matches what other templates do. Fixes: 71ebc4d1b27d ("crypto: chacha20poly1305 - Add a ChaCha20-Poly1305 AEAD construction, RFC7539") Cc: <stable@vger.kernel.org> # v4.2+ Cc: Martin Willi <martin@strongswan.org> Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Martin Willi <martin@strongswan.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21sched/x86: Save [ER]FLAGS on context switchPeter Zijlstra
commit 6690e86be83ac75832e461c141055b5d601c0a6d upstream. Effectively reverts commit: 2c7577a75837 ("sched/x86_64: Don't save flags on context switch") Specifically because SMAP uses FLAGS.AC which invalidates the claim that the kernel has clean flags. In particular; while preemption from interrupt return is fine (the IRET frame on the exception stack contains FLAGS) it breaks any code that does synchonous scheduling, including preempt_enable(). This has become a significant issue ever since commit: 5b24a7a2aa20 ("Add 'unsafe' user access functions for batched accesses") provided for means of having 'normal' C code between STAC / CLAC, exposing the FLAGS.AC state. So far this hasn't led to trouble, however fix it before it comes apart. Reported-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org Fixes: 5b24a7a2aa20 ("Add 'unsafe' user access functions for batched accesses") Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21arm64: Save and restore OSDLR_EL1 across suspend/resumeJean-Philippe Brucker
commit 827a108e354db633698f0b4a10c1ffd2b1f8d1d0 upstream. When the CPU comes out of suspend, the firmware may have modified the OS Double Lock Register. Save it in an unused slot of cpu_suspend_ctx, and restore it on resume. Cc: <stable@vger.kernel.org> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21arm64: Clear OSDLR_EL1 on CPU bootJean-Philippe Brucker
commit 6fda41bf12615ee7c3ddac88155099b1a8cf8d00 upstream. Some firmwares may reboot CPUs with OS Double Lock set. Make sure that it is unlocked, in order to use debug exceptions. Cc: <stable@vger.kernel.org> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21arm64: compat: Reduce address limitVincenzo Frascino
commit d263119387de9975d2acba1dfd3392f7c5979c18 upstream. Currently, compat tasks running on arm64 can allocate memory up to TASK_SIZE_32 (UL(0x100000000)). This means that mmap() allocations, if we treat them as returning an array, are not compliant with the sections 6.5.8 of the C standard (C99) which states that: "If the expression P points to an element of an array object and the expression Q points to the last element of the same array object, the pointer expression Q+1 compares greater than P". Redefine TASK_SIZE_32 to address the issue. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Jann Horn <jannh@google.com> Cc: <stable@vger.kernel.org> Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> [will: fixed typo in comment] Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21power: supply: axp288_charger: Fix unchecked return valueGustavo A. R. Silva
commit c3422ad5f84a66739ec6a37251ca27638c85b6be upstream. Currently there is no check on platform_get_irq() return value in case it fails, hence never actually reporting any errors and causing unexpected behavior when using such value as argument for function regmap_irq_get_virq(). Fix this by adding a proper check, a message reporting any errors and returning *pirq* Addresses-Coverity-ID: 1443940 ("Improper use of negative value") Fixes: 843735b788a4 ("power: axp288_charger: axp288 charger driver") Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ARM: exynos: Fix a leaked reference by adding missing of_node_putWen Yang
commit 629266bf7229cd6a550075f5961f95607b823b59 upstream. The call to of_get_next_child returns a node pointer with refcount incremented thus it must be explicitly decremented after the last usage. Detected by coccinelle with warnings like: arch/arm/mach-exynos/firmware.c:201:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 193, but without a corresponding object release within this function. Cc: stable@vger.kernel.org Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ARM: dts: exynos: Fix audio (microphone) routing on Odroid XU3Sylwester Nawrocki
commit 9b23e1a3e8fde76e8cc0e366ab1ed4ffb4440feb upstream. The name of CODEC input widget to which microphone is connected through the "Headphone" jack is "IN12" not "IN1". This fixes microphone support on Odroid XU3. Cc: <stable@vger.kernel.org> # v4.14+ Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21ARM: dts: exynos: Fix interrupt for shared EINTs on Exynos5260Stuart Menefy
commit b7ed69d67ff0788d8463e599dd5dd1b45c701a7e upstream. Fix the interrupt information for the GPIO lines with a shared EINT interrupt. Fixes: 16d7ff2642e7 ("ARM: dts: add dts files for exynos5260 SoC") Cc: stable@vger.kernel.org Signed-off-by: Stuart Menefy <stuart.menefy@mathembedded.com> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21objtool: Fix function fallthrough detectionJosh Poimboeuf
commit e6f393bc939d566ce3def71232d8013de9aaadde upstream. When a function falls through to the next function due to a compiler bug, objtool prints some obscure warnings. For example: drivers/regulator/core.o: warning: objtool: regulator_count_voltages()+0x95: return with modified stack frame drivers/regulator/core.o: warning: objtool: regulator_count_voltages()+0x0: stack state mismatch: cfa1=7+32 cfa2=7+8 Instead it should be printing: drivers/regulator/core.o: warning: objtool: regulator_supply_is_couple() falls through to next function regulator_count_voltages() This used to work, but was broken by the following commit: 13810435b9a7 ("objtool: Support GCC 8's cold subfunctions") The padding nops at the end of a function aren't actually part of the function, as defined by the symbol table. So the 'func' variable in validate_branch() is getting cleared to NULL when a padding nop is encountered, breaking the fallthrough detection. If the current instruction doesn't have a function associated with it, just consider it to be part of the previously detected function by not overwriting the previous value of 'func'. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Fixes: 13810435b9a7 ("objtool: Support GCC 8's cold subfunctions") Link: http://lkml.kernel.org/r/546d143820cd08a46624ae8440d093dd6c902cae.1557766718.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21x86/speculation/mds: Improve CPU buffer clear documentationAndy Lutomirski
commit 9d8d0294e78a164d407133dea05caf4b84247d6a upstream. On x86_64, all returns to usermode go through prepare_exit_to_usermode(), with the sole exception of do_nmi(). This even includes machine checks -- this was added several years ago to support MCE recovery. Update the documentation. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jon Masters <jcm@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Fixes: 04dcbdb80578 ("x86/speculation/mds: Clear CPU buffers on exit to user") Link: http://lkml.kernel.org/r/999fa9e126ba6a48e9d214d2f18dbde5c62ac55c.1557865329.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21x86/speculation/mds: Revert CPU buffer clear on double fault exitAndy Lutomirski
commit 88640e1dcd089879530a49a8d212d1814678dfe7 upstream. The double fault ESPFIX path doesn't return to user mode at all -- it returns back to the kernel by simulating a #GP fault. prepare_exit_to_usermode() will run on the way out of general_protection before running user code. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jon Masters <jcm@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Fixes: 04dcbdb80578 ("x86/speculation/mds: Clear CPU buffers on exit to user") Link: http://lkml.kernel.org/r/ac97612445c0a44ee10374f6ea79c222fe22a5c4.1557865329.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21PCI: hv: Add pci_destroy_slot() in pci_devices_present_work(), if necessaryDexuan Cui
[ Upstream commit 340d455699400f2c2c0f9b3f703ade3085cdb501 ] When we hot-remove a device, usually the host sends us a PCI_EJECT message, and a PCI_BUS_RELATIONS message with bus_rel->device_count == 0. When we execute the quick hot-add/hot-remove test, the host may not send us the PCI_EJECT message if the guest has not fully finished the initialization by sending the PCI_RESOURCES_ASSIGNED* message to the host, so it's potentially unsafe to only depend on the pci_destroy_slot() in hv_eject_device_work() because the code path create_root_hv_pci_bus() -> hv_pci_assign_slots() is not called in this case. Note: in this case, the host still sends the guest a PCI_BUS_RELATIONS message with bus_rel->device_count == 0. In the quick hot-add/hot-remove test, we can have such a race before the code path pci_devices_present_work() -> new_pcichild_device() adds the new device into the hbus->children list, we may have already received the PCI_EJECT message, and since the tasklet handler hv_pci_onchannelcallback() may fail to find the "hpdev" by calling get_pcichild_wslot(hbus, dev_message->wslot.slot) hv_pci_eject_device() is not called; Later, by continuing execution create_root_hv_pci_bus() -> hv_pci_assign_slots() creates the slot and the PCI_BUS_RELATIONS message with bus_rel->device_count == 0 removes the device from hbus->children, and we end up being unable to remove the slot in hv_pci_remove() -> hv_pci_remove_slots() Remove the slot in pci_devices_present_work() when the device is removed to address this race. pci_devices_present_work() and hv_eject_device_work() run in the singled-threaded hbus->wq, so there is not a double-remove issue for the slot. We cannot offload hv_pci_eject_device() from hv_pci_onchannelcallback() to the workqueue, because we need the hv_pci_onchannelcallback() synchronously call hv_pci_eject_device() to poll the channel ringbuffer to work around the "hangs in hv_compose_msi_msg()" issue fixed in commit de0aa7b2f97d ("PCI: hv: Fix 2 hang issues in hv_compose_msi_msg()") Fixes: a15f2c08c708 ("PCI: hv: support reporting serial number as slot information") Signed-off-by: Dexuan Cui <decui@microsoft.com> [lorenzo.pieralisi@arm.com: rewritten commit log] Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Stephen Hemminger <stephen@networkplumber.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-21PCI: hv: Add hv_pci_remove_slots() when we unload the driverDexuan Cui
[ Upstream commit 15becc2b56c6eda3d9bf5ae993bafd5661c1fad1 ] When we unload the pci-hyperv host controller driver, the host does not send us a PCI_EJECT message. In this case we also need to make sure the sysfs PCI slot directory is removed, otherwise a command on a slot file eg: "cat /sys/bus/pci/slots/2/address" will trigger a "BUG: unable to handle kernel paging request" and, if we unload/reload the driver several times we would end up with stale slot entries in PCI slot directories in /sys/bus/pci/slots/ root@localhost:~# ls -rtl /sys/bus/pci/slots/ total 0 drwxr-xr-x 2 root root 0 Feb 7 10:49 2 drwxr-xr-x 2 root root 0 Feb 7 10:49 2-1 drwxr-xr-x 2 root root 0 Feb 7 10:51 2-2 Add the missing code to remove the PCI slot and fix the current behaviour. Fixes: a15f2c08c708 ("PCI: hv: support reporting serial number as slot information") Signed-off-by: Dexuan Cui <decui@microsoft.com> [lorenzo.pieralisi@arm.com: reformatted the log] Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Stephen Hemminger <sthemmin@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-21PCI: hv: Fix a memory leak in hv_eject_device_work()Dexuan Cui
[ Upstream commit 05f151a73ec2b23ffbff706e5203e729a995cdc2 ] When a device is created in new_pcichild_device(), hpdev->refs is set to 2 (i.e. the initial value of 1 plus the get_pcichild()). When we hot remove the device from the host, in a Linux VM we first call hv_pci_eject_device(), which increases hpdev->refs by get_pcichild() and then schedules a work of hv_eject_device_work(), so hpdev->refs becomes 3 (let's ignore the paired get/put_pcichild() in other places). But in hv_eject_device_work(), currently we only call put_pcichild() twice, meaning the 'hpdev' struct can't be freed in put_pcichild(). Add one put_pcichild() to fix the memory leak. The device can also be removed when we run "rmmod pci-hyperv". On this path (hv_pci_remove() -> hv_pci_bus_exit() -> hv_pci_devices_present()), hpdev->refs is 2, and we do correctly call put_pcichild() twice in pci_devices_present_work(). Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs") Signed-off-by: Dexuan Cui <decui@microsoft.com> [lorenzo.pieralisi@arm.com: commit log rework] Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Stephen Hemminger <stephen@networkplumber.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-21locking/rwsem: Prevent decrement of reader count before incrementWaiman Long
[ Upstream commit a9e9bcb45b1525ba7aea26ed9441e8632aeeda58 ] During my rwsem testing, it was found that after a down_read(), the reader count may occasionally become 0 or even negative. Consequently, a writer may steal the lock at that time and execute with the reader in parallel thus breaking the mutual exclusion guarantee of the write lock. In other words, both readers and writer can become rwsem owners simultaneously. The current reader wakeup code does it in one pass to clear waiter->task and put them into wake_q before fully incrementing the reader count. Once waiter->task is cleared, the corresponding reader may see it, finish the critical section and do unlock to decrement the count before the count is incremented. This is not a problem if there is only one reader to wake up as the count has been pre-incremented by 1. It is a problem if there are more than one readers to be woken up and writer can steal the lock. The wakeup was actually done in 2 passes before the following v4.9 commit: 70800c3c0cc5 ("locking/rwsem: Scan the wait_list for readers only once") To fix this problem, the wakeup is now done in two passes again. In the first pass, we collect the readers and count them. The reader count is then fully incremented. In the second pass, the waiter->task is then cleared and they are put into wake_q to be woken up later. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: huang ying <huang.ying.caritas@gmail.com> Fixes: 70800c3c0cc5 ("locking/rwsem: Scan the wait_list for readers only once") Link: http://lkml.kernel.org/r/20190428212557.13482-2-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-21net: core: another layer of lists, around PF_MEMALLOC skb handlingSasha Levin
[ Upstream commit 78ed8cc25986ac5c21762eeddc1e86e94d422e36 ] First example of a layer splitting the list (rather than merely taking individual packets off it). Involves new list.h function, list_cut_before(), like list_cut_position() but cuts on the other side of the given entry. Signed-off-by: Edward Cree <ecree@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net> [sl: cut out non list.h bits, we only want list_cut_before] Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-16Linux 4.14.120Greg Kroah-Hartman
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