linux-toradex.git/fs, branch toradex_5.3.y

CIFS: Fix retry mid list corruption on reconnects

2019-11-10T10:34:56+00:00

commit abe57073d08c13b95a46ccf48cc9dc957d5c6fdb upstream.

When the client hits reconnect it iterates over the mid
pending queue marking entries for retry and moving them
to a temporary list to issue callbacks later without holding
GlobalMid_Lock. In the same time there is no guarantee that
mids can't be removed from the temporary list or even
freed completely by another thread. It may cause a temporary
list corruption:

[  430.454897] list_del corruption. prev->next should be ffff98d3a8f316c0, but was 2e885cb266355469
[  430.464668] ------------[ cut here ]------------
[  430.466569] kernel BUG at lib/list_debug.c:51!
[  430.468476] invalid opcode: 0000 [#1] SMP PTI
[  430.470286] CPU: 0 PID: 13267 Comm: cifsd Kdump: loaded Not tainted 5.4.0-rc3+ #19
[  430.473472] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[  430.475872] RIP: 0010:__list_del_entry_valid.cold+0x31/0x55
...
[  430.510426] Call Trace:
[  430.511500]  cifs_reconnect+0x25e/0x610 [cifs]
[  430.513350]  cifs_readv_from_socket+0x220/0x250 [cifs]
[  430.515464]  cifs_read_from_socket+0x4a/0x70 [cifs]
[  430.517452]  ? try_to_wake_up+0x212/0x650
[  430.519122]  ? cifs_small_buf_get+0x16/0x30 [cifs]
[  430.521086]  ? allocate_buffers+0x66/0x120 [cifs]
[  430.523019]  cifs_demultiplex_thread+0xdc/0xc30 [cifs]
[  430.525116]  kthread+0xfb/0x130
[  430.526421]  ? cifs_handle_standard+0x190/0x190 [cifs]
[  430.528514]  ? kthread_park+0x90/0x90
[  430.530019]  ret_from_fork+0x35/0x40

Fix this by obtaining extra references for mids being retried
and marking them as MID_DELETED which indicates that such a mid
has been dequeued from the pending list.

Also move mid cleanup logic from DeleteMidQEntry to
_cifs_mid_q_entry_release which is called when the last reference
to a particular mid is put. This allows to avoid any use-after-free
of response buffers.

The patch needs to be backported to stable kernels. A stable tag
is not mentioned below because the patch doesn't apply cleanly
to any actively maintained stable kernel.

Reviewed-by: Ronnie Sahlberg 
Reviewed-and-tested-by: David Wysochanski 
Signed-off-by: Pavel Shilovsky 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

cifs: Fix cifsInodeInfo lock_sem deadlock when reconnect occurs

2019-11-10T10:34:27+00:00

[ Upstream commit d46b0da7a33dd8c99d969834f682267a45444ab3 ]

There's a deadlock that is possible and can easily be seen with
a test where multiple readers open/read/close of the same file
and a disruption occurs causing reconnect.  The deadlock is due
a reader thread inside cifs_strict_readv calling down_read and
obtaining lock_sem, and then after reconnect inside
cifs_reopen_file calling down_read a second time.  If in
between the two down_read calls, a down_write comes from
another process, deadlock occurs.

        CPU0                    CPU1
        ----                    ----
cifs_strict_readv()
 down_read(&cifsi->lock_sem);
                               _cifsFileInfo_put
                                  OR
                               cifs_new_fileinfo
                                down_write(&cifsi->lock_sem);
cifs_reopen_file()
 down_read(&cifsi->lock_sem);

Fix the above by changing all down_write(lock_sem) calls to
down_write_trylock(lock_sem)/msleep() loop, which in turn
makes the second down_read call benign since it will never
block behind the writer while holding lock_sem.

Signed-off-by: Dave Wysochanski 
Suggested-by: Ronnie Sahlberg 
Reviewed--by: Ronnie Sahlberg 
Reviewed-by: Pavel Shilovsky 
Signed-off-by: Sasha Levin

io_uring: ensure we clear io_kiocb->result before each issue

2019-11-06T12:09:25+00:00

commit 6873e0bd6a9cb14ecfadd89d9ed9698ff1761902 upstream.

We use io_kiocb->result == -EAGAIN as a way to know if we need to
re-submit a polled request, as -EAGAIN reporting happens out-of-line
for IO submission failures. This field is cleared when we originally
allocate the request, but it isn't reset when we retry the submission
from async context. This can cause issues where we think something
needs a re-issue, but we're really just reading stale data.

Reset ->result whenever we re-prep a request for polled submission.

Cc: stable@vger.kernel.org
Fixes: 9e645e1105ca ("io_uring: add support for sqe links")
Reported-by: Bijan Mottahedeh 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

NFS: Fix an RCU lock leak in nfs4_refresh_delegation_stateid()

2019-11-06T12:09:24+00:00

commit 79cc55422ce99be5964bde208ba8557174720893 upstream.

A typo in nfs4_refresh_delegation_stateid() means we're leaking an
RCU lock, and always returning a value of 'false'. As the function
description states, we were always supposed to return 'true' if a
matching delegation was found.

Fixes: 12f275cdd163 ("NFSv4: Retry CLOSE and DELEGRETURN on NFS4ERR_OLD_STATEID.")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Trond Myklebust 
Signed-off-by: Anna Schumaker 
Signed-off-by: Greg Kroah-Hartman

fuse: truncate pending writes on O_TRUNC

2019-11-06T12:08:54+00:00

commit e4648309b85a78f8c787457832269a8712a8673e upstream.

Make sure cached writes are not reordered around open(..., O_TRUNC), with
the obvious wrong results.

Fixes: 4d99ff8f12eb ("fuse: Turn writeback cache on")
Cc:  # v3.15+
Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

fuse: flush dirty data/metadata before non-truncate setattr

2019-11-06T12:08:54+00:00

commit b24e7598db62386a95a3c8b9c75630c5d56fe077 upstream.

If writeback cache is enabled, then writes might get reordered with
chmod/chown/utimes.  The problem with this is that performing the write in
the fuse daemon might itself change some of these attributes.  In such case
the following sequence of operations will result in file ending up with the
wrong mode, for example:

  int fd = open ("suid", O_WRONLY|O_CREAT|O_EXCL);
  write (fd, "1", 1);
  fchown (fd, 0, 0);
  fchmod (fd, 04755);
  close (fd);

This patch fixes this by flushing pending writes before performing
chown/chmod/utimes.

Reported-by: Giuseppe Scrivano 
Tested-by: Giuseppe Scrivano 
Fixes: 4d99ff8f12eb ("fuse: Turn writeback cache on")
Cc:  # v3.15+
Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

NFSv4: Fix leak of clp->cl_acceptor string

2019-11-06T12:08:45+00:00

[ Upstream commit 1047ec868332034d1fbcb2fae19fe6d4cb869ff2 ]

Our client can issue multiple SETCLIENTID operations to the same
server in some circumstances. Ensure that calls to
nfs4_proc_setclientid() after the first one do not overwrite the
previously allocated cl_acceptor string.

unreferenced object 0xffff888461031800 (size 32):
  comm "mount.nfs", pid 2227, jiffies 4294822467 (age 1407.749s)
  hex dump (first 32 bytes):
    6e 66 73 40 6b 6c 69 6d 74 2e 69 62 2e 31 30 31  nfs@klimt.ib.101
    35 67 72 61 6e 67 65 72 2e 6e 65 74 00 00 00 00  5granger.net....
  backtrace:
    [<00000000ab820188>] __kmalloc+0x128/0x176
    [<00000000eeaf4ec8>] gss_stringify_acceptor+0xbd/0x1a7 [auth_rpcgss]
    [<00000000e85e3382>] nfs4_proc_setclientid+0x34e/0x46c [nfsv4]
    [<000000003d9cf1fa>] nfs40_discover_server_trunking+0x7a/0xed [nfsv4]
    [<00000000b81c3787>] nfs4_discover_server_trunking+0x81/0x244 [nfsv4]
    [<000000000801b55f>] nfs4_init_client+0x1b0/0x238 [nfsv4]
    [<00000000977daf7f>] nfs4_set_client+0xfe/0x14d [nfsv4]
    [<0000000053a68a2a>] nfs4_create_server+0x107/0x1db [nfsv4]
    [<0000000088262019>] nfs4_remote_mount+0x2c/0x59 [nfsv4]
    [<00000000e84a2fd0>] legacy_get_tree+0x2d/0x4c
    [<00000000797e947c>] vfs_get_tree+0x20/0xc7
    [<00000000ecabaaa8>] fc_mount+0xe/0x36
    [<00000000f15fafc2>] vfs_kern_mount+0x74/0x8d
    [<00000000a3ff4e26>] nfs_do_root_mount+0x8a/0xa3 [nfsv4]
    [<00000000d1c2b337>] nfs4_try_mount+0x58/0xad [nfsv4]
    [<000000004c9bddee>] nfs_fs_mount+0x820/0x869 [nfs]

Fixes: f11b2a1cfbf5 ("nfs4: copy acceptor name from context ... ")
Signed-off-by: Chuck Lever 
Signed-off-by: Anna Schumaker 
Signed-off-by: Sasha Levin

btrfs: silence maybe-uninitialized warning in clone_range

2019-11-06T12:08:29+00:00

[ Upstream commit 431d39887d6273d6d84edf3c2eab09f4200e788a ]

GCC throws warning message as below:

‘clone_src_i_size’ may be used uninitialized in this function
[-Wmaybe-uninitialized]
 #define IS_ALIGNED(x, a)  (((x) & ((typeof(x))(a) - 1)) == 0)
                       ^
fs/btrfs/send.c:5088:6: note: ‘clone_src_i_size’ was declared here
 u64 clone_src_i_size;
   ^
The clone_src_i_size is only used as call-by-reference
in a call to get_inode_info().

Silence the warning by initializing clone_src_i_size to 0.

Note that the warning is a false positive and reported by older versions
of GCC (eg. 7.x) but not eg 9.x. As there have been numerous people, the
patch is applied. Setting clone_src_i_size to 0 does not otherwise make
sense and would not do any action in case the code changes in the future.

Signed-off-by: Austin Kim 
Reviewed-by: David Sterba 
[ add note ]
Signed-off-by: David Sterba 
Signed-off-by: Sasha Levin

fs: ocfs2: fix a possible null-pointer dereference in ocfs2_info_scan_inode_alloc()

2019-11-06T12:08:29+00:00

[ Upstream commit 2abb7d3b12d007c30193f48bebed781009bebdd2 ]

In ocfs2_info_scan_inode_alloc(), there is an if statement on line 283
to check whether inode_alloc is NULL:

    if (inode_alloc)

When inode_alloc is NULL, it is used on line 287:

    ocfs2_inode_lock(inode_alloc, &bh, 0);
        ocfs2_inode_lock_full_nested(inode, ...)
            struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

Thus, a possible null-pointer dereference may occur.

To fix this bug, inode_alloc is checked on line 286.

This bug is found by a static analysis tool STCheck written by us.

Link: http://lkml.kernel.org/r/20190726033717.32359-1-baijiaju1990@gmail.com
Signed-off-by: Jia-Ju Bai 
Reviewed-by: Joseph Qi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Junxiao Bi 
Cc: Changwei Ge 
Cc: Gang He 
Cc: Jun Piao 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

fs: ocfs2: fix a possible null-pointer dereference in ocfs2_write_end_nolock()

2019-11-06T12:08:28+00:00

[ Upstream commit 583fee3e12df0e6f1f66f063b989d8e7fed0e65a ]

In ocfs2_write_end_nolock(), there are an if statement on lines 1976,
2047 and 2058, to check whether handle is NULL:

    if (handle)

When handle is NULL, it is used on line 2045:

	ocfs2_update_inode_fsync_trans(handle, inode, 1);
        oi->i_sync_tid = handle->h_transaction->t_tid;

Thus, a possible null-pointer dereference may occur.

To fix this bug, handle is checked before calling
ocfs2_update_inode_fsync_trans().

This bug is found by a static analysis tool STCheck written by us.

Link: http://lkml.kernel.org/r/20190726033705.32307-1-baijiaju1990@gmail.com
Signed-off-by: Jia-Ju Bai 
Reviewed-by: Joseph Qi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Junxiao Bi 
Cc: Changwei Ge 
Cc: Gang He 
Cc: Jun Piao 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin