linux-toradex.git/sound/core, branch v4.4.26

ALSA: timer: fix NULL pointer dereference on memory allocation failure

2016-09-15T06:27:54+00:00

commit 8ddc05638ee42b18ba4fe99b5fb647fa3ad20456 upstream.

I hit this with syzkaller:

    kasan: CONFIG_KASAN_INLINE enabled
    kasan: GPF could be caused by NULL-ptr deref or user memory access
    general protection fault: 0000 [#1] PREEMPT SMP KASAN
    CPU: 0 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #190
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
    task: ffff88011278d600 task.stack: ffff8801120c0000
    RIP: 0010:[]  [] snd_hrtimer_start+0x77/0x100
    RSP: 0018:ffff8801120c7a60  EFLAGS: 00010006
    RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000007
    RDX: 0000000000000009 RSI: 1ffff10023483091 RDI: 0000000000000048
    RBP: ffff8801120c7a78 R08: ffff88011a5cf768 R09: ffff88011a5ba790
    R10: 0000000000000002 R11: ffffed00234b9ef1 R12: ffff880114843980
    R13: ffffffff84213c00 R14: ffff880114843ab0 R15: 0000000000000286
    FS:  00007f72958f3700(0000) GS:ffff88011aa00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000603001 CR3: 00000001126ab000 CR4: 00000000000006f0
    Stack:
     ffff880114843980 ffff880111eb2dc0 ffff880114843a34 ffff8801120c7ad0
     ffffffff82c81ab1 0000000000000000 ffffffff842138e0 0000000100000000
     ffff880111eb2dd0 ffff880111eb2dc0 0000000000000001 ffff880111eb2dc0
    Call Trace:
     [] snd_timer_start1+0x331/0x670
     [] snd_timer_start+0x5d/0xa0
     [] snd_timer_user_ioctl+0x88e/0x2830
     [] ? __follow_pte.isra.49+0x430/0x430
     [] ? snd_timer_pause+0x80/0x80
     [] ? do_wp_page+0x3aa/0x1c90
     [] ? put_prev_entity+0x108f/0x21a0
     [] ? snd_timer_pause+0x80/0x80
     [] do_vfs_ioctl+0x193/0x1050
     [] ? cpuacct_account_field+0x12f/0x1a0
     [] ? ioctl_preallocate+0x200/0x200
     [] ? syscall_trace_enter+0x3cf/0xdb0
     [] ? __context_tracking_exit.part.4+0x9a/0x1e0
     [] ? exit_to_usermode_loop+0x190/0x190
     [] ? check_preemption_disabled+0x37/0x1e0
     [] ? security_file_ioctl+0x89/0xb0
     [] SyS_ioctl+0x8f/0xc0
     [] ? do_vfs_ioctl+0x1050/0x1050
     [] do_syscall_64+0x1c4/0x4e0
     [] entry_SYSCALL64_slow_path+0x25/0x25
    Code: c7 c7 c4 b9 c8 82 48 89 d9 4c 89 ee e8 63 88 7f fe e8 7e 46 7b fe 48 8d 7b 48 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 84 c0 7e 65 80 7b 48 00 74 0e e8 52 46
    RIP  [] snd_hrtimer_start+0x77/0x100
     RSP 
    ---[ end trace 5955b08db7f2b029 ]---

This can happen if snd_hrtimer_open() fails to allocate memory and
returns an error, which is currently not checked by snd_timer_open():

    ioctl(SNDRV_TIMER_IOCTL_SELECT)
     - snd_timer_user_tselect()
	- snd_timer_close()
	   - snd_hrtimer_close()
	      - (struct snd_timer *) t->private_data = NULL
        - snd_timer_open()
           - snd_hrtimer_open()
              - kzalloc() fails; t->private_data is still NULL

    ioctl(SNDRV_TIMER_IOCTL_START)
     - snd_timer_user_start()
	- snd_timer_start()
	   - snd_timer_start1()
	      - snd_hrtimer_start()
		- t->private_data == NULL // boom

Signed-off-by: Vegard Nossum 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE

2016-09-15T06:27:54+00:00

commit 6b760bb2c63a9e322c0e4a0b5daf335ad93d5a33 upstream.

I got this:

    divide error: 0000 [#1] PREEMPT SMP KASAN
    CPU: 1 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #189
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
    task: ffff8801120a9580 task.stack: ffff8801120b0000
    RIP: 0010:[]  [] snd_hrtimer_callback+0x1da/0x3f0
    RSP: 0018:ffff88011aa87da8  EFLAGS: 00010006
    RAX: 0000000000004f76 RBX: ffff880112655e88 RCX: 0000000000000000
    RDX: 0000000000000000 RSI: ffff880112655ea0 RDI: 0000000000000001
    RBP: ffff88011aa87e00 R08: ffff88013fff905c R09: ffff88013fff9048
    R10: ffff88013fff9050 R11: 00000001050a7b8c R12: ffff880114778a00
    R13: ffff880114778ab4 R14: ffff880114778b30 R15: 0000000000000000
    FS:  00007f071647c700(0000) GS:ffff88011aa80000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000603001 CR3: 0000000112021000 CR4: 00000000000006e0
    Stack:
     0000000000000000 ffff880114778ab8 ffff880112655ea0 0000000000004f76
     ffff880112655ec8 ffff880112655e80 ffff880112655e88 ffff88011aa98fc0
     00000000b97ccf2b dffffc0000000000 ffff88011aa98fc0 ffff88011aa87ef0
    Call Trace:
     
     [] __hrtimer_run_queues+0x347/0xa00
     [] ? snd_hrtimer_close+0x130/0x130
     [] ? retrigger_next_event+0x1b0/0x1b0
     [] ? hrtimer_interrupt+0x136/0x4b0
     [] hrtimer_interrupt+0x1b0/0x4b0
     [] local_apic_timer_interrupt+0x6e/0xf0
     [] ? kvm_guest_apic_eoi_write+0x13/0xc0
     [] smp_apic_timer_interrupt+0x76/0xa0
     [] apic_timer_interrupt+0x8c/0xa0
     
     [] ? _raw_spin_unlock_irqrestore+0x2c/0x60
     [] snd_timer_start1+0xdd/0x670
     [] snd_timer_continue+0x45/0x80
     [] snd_timer_user_ioctl+0x1030/0x2830
     [] ? __follow_pte.isra.49+0x430/0x430
     [] ? snd_timer_pause+0x80/0x80
     [] ? do_wp_page+0x3aa/0x1c90
     [] ? handle_mm_fault+0xbc8/0x27f0
     [] ? __pmd_alloc+0x370/0x370
     [] ? snd_timer_pause+0x80/0x80
     [] do_vfs_ioctl+0x193/0x1050
     [] ? ioctl_preallocate+0x200/0x200
     [] ? syscall_trace_enter+0x3cf/0xdb0
     [] ? __context_tracking_exit.part.4+0x9a/0x1e0
     [] ? exit_to_usermode_loop+0x190/0x190
     [] ? check_preemption_disabled+0x37/0x1e0
     [] ? security_file_ioctl+0x89/0xb0
     [] SyS_ioctl+0x8f/0xc0
     [] ? do_vfs_ioctl+0x1050/0x1050
     [] do_syscall_64+0x1c4/0x4e0
     [] entry_SYSCALL64_slow_path+0x25/0x25
    Code: e8 fc 42 7b fe 8b 0d 06 8a 50 03 49 0f af cf 48 85 c9 0f 88 7c 01 00 00 48 89 4d a8 e8 e0 42 7b fe 48 8b 45 c0 48 8b 4d a8 48 99 <48> f7 f9 49 01 c7 e8 cb 42 7b fe 48 8b 55 d0 48 b8 00 00 00 00
    RIP  [] snd_hrtimer_callback+0x1da/0x3f0
     RSP 
    ---[ end trace 6aa380f756a21074 ]---

The problem happens when you call ioctl(SNDRV_TIMER_IOCTL_CONTINUE) on a
completely new/unused timer -- it will have ->sticks == 0, which causes a
divide by 0 in snd_hrtimer_callback().

Signed-off-by: Vegard Nossum 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: timer: fix NULL pointer dereference in read()/ioctl() race

2016-09-15T06:27:54+00:00

commit 11749e086b2766cccf6217a527ef5c5604ba069c upstream.

I got this with syzkaller:

    ==================================================================
    BUG: KASAN: null-ptr-deref on address 0000000000000020
    Read of size 32 by task syz-executor/22519
    CPU: 1 PID: 22519 Comm: syz-executor Not tainted 4.8.0-rc2+ #169
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2
    014
     0000000000000001 ffff880111a17a00 ffffffff81f9f141 ffff880111a17a90
     ffff880111a17c50 ffff880114584a58 ffff880114584a10 ffff880111a17a80
     ffffffff8161fe3f ffff880100000000 ffff880118d74a48 ffff880118d74a68
    Call Trace:
     [] dump_stack+0x83/0xb2
     [] kasan_report_error+0x41f/0x4c0
     [] kasan_report+0x34/0x40
     [] ? snd_timer_user_read+0x554/0x790
     [] check_memory_region+0x13e/0x1a0
     [] kasan_check_read+0x11/0x20
     [] snd_timer_user_read+0x554/0x790
     [] ? snd_timer_user_info_compat.isra.5+0x2b0/0x2b0
     [] ? proc_fault_inject_write+0x1c1/0x250
     [] ? next_tgid+0x2a0/0x2a0
     [] ? do_group_exit+0x108/0x330
     [] ? fsnotify+0x72a/0xca0
     [] __vfs_read+0x10e/0x550
     [] ? snd_timer_user_info_compat.isra.5+0x2b0/0x2b0
     [] ? do_sendfile+0xc50/0xc50
     [] ? __fsnotify_update_child_dentry_flags+0x60/0x60
     [] ? kcov_ioctl+0x56/0x190
     [] ? common_file_perm+0x2e2/0x380
     [] ? __fsnotify_parent+0x5e/0x2b0
     [] ? security_file_permission+0x86/0x1e0
     [] ? rw_verify_area+0xe5/0x2b0
     [] vfs_read+0x115/0x330
     [] SyS_read+0xd1/0x1a0
     [] ? vfs_write+0x4b0/0x4b0
     [] ? __this_cpu_preempt_check+0x1c/0x20
     [] ? __context_tracking_exit.part.4+0x3a/0x1e0
     [] ? vfs_write+0x4b0/0x4b0
     [] do_syscall_64+0x1c4/0x4e0
     [] ? syscall_return_slowpath+0x16c/0x1d0
     [] entry_SYSCALL64_slow_path+0x25/0x25
    ==================================================================

There are a couple of problems that I can see:

 - ioctl(SNDRV_TIMER_IOCTL_SELECT), which potentially sets
   tu->queue/tu->tqueue to NULL on memory allocation failure, so read()
   would get a NULL pointer dereference like the above splat

 - the same ioctl() can free tu->queue/to->tqueue which means read()
   could potentially see (and dereference) the freed pointer

We can fix both by taking the ioctl_lock mutex when dereferencing
->queue/->tqueue, since that's always held over all the ioctl() code.

Just looking at the code I find it likely that there are more problems
here such as tu->qhead pointing outside the buffer if the size is
changed concurrently using SNDRV_TIMER_IOCTL_PARAMS.

Signed-off-by: Vegard Nossum 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: rawmidi: Fix possible deadlock with virmidi registration

2016-09-15T06:27:53+00:00

commit 816f318b2364262a51024096da7ca3b84e78e3b5 upstream.

When a seq-virmidi driver is initialized, it registers a rawmidi
instance with its callback to create an associated seq kernel client.
Currently it's done throughly in rawmidi's register_mutex context.
Recently it was found that this may lead to a deadlock another rawmidi
device that is being attached with the sequencer is accessed, as both
open with the same register_mutex.  This was actually triggered by
syzkaller, as Dmitry Vyukov reported:

======================================================
 [ INFO: possible circular locking dependency detected ]
 4.8.0-rc1+ #11 Not tainted
 -------------------------------------------------------
 syz-executor/7154 is trying to acquire lock:
  (register_mutex#5){+.+.+.}, at: [] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341

 but task is already holding lock:
  (&grp->list_mutex){++++.+}, at: [] check_and_subscribe_port+0x5b/0x5c0 sound/core/seq/seq_ports.c:495

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (&grp->list_mutex){++++.+}:
    [] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746
    [] down_read+0x49/0xc0 kernel/locking/rwsem.c:22
    [<     inline     >] deliver_to_subscribers sound/core/seq/seq_clientmgr.c:681
    [] snd_seq_deliver_event+0x35e/0x890 sound/core/seq/seq_clientmgr.c:822
    [] > snd_seq_kernel_client_dispatch+0x126/0x170 sound/core/seq/seq_clientmgr.c:2418
    [] snd_seq_system_broadcast+0xb2/0xf0 sound/core/seq/seq_system.c:101
    [] snd_seq_create_kernel_client+0x24a/0x330 sound/core/seq/seq_clientmgr.c:2297
    [<     inline     >] snd_virmidi_dev_attach_seq sound/core/seq/seq_virmidi.c:383
    [] snd_virmidi_dev_register+0x29f/0x750 sound/core/seq/seq_virmidi.c:450
    [] snd_rawmidi_dev_register+0x30c/0xd40 sound/core/rawmidi.c:1645
    [] __snd_device_register.part.0+0x63/0xc0 sound/core/device.c:164
    [<     inline     >] __snd_device_register sound/core/device.c:162
    [] snd_device_register_all+0xad/0x110 sound/core/device.c:212
    [] snd_card_register+0xef/0x6c0 sound/core/init.c:749
    [] snd_virmidi_probe+0x3ef/0x590 sound/drivers/virmidi.c:123
    [] platform_drv_probe+0x8b/0x170 drivers/base/platform.c:564
    ......

 -> #0 (register_mutex#5){+.+.+.}:
    [<     inline     >] check_prev_add kernel/locking/lockdep.c:1829
    [<     inline     >] check_prevs_add kernel/locking/lockdep.c:1939
    [<     inline     >] validate_chain kernel/locking/lockdep.c:2266
    [] __lock_acquire+0x4d44/0x4d80 kernel/locking/lockdep.c:3335
    [] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746
    [<     inline     >] __mutex_lock_common kernel/locking/mutex.c:521
    [] mutex_lock_nested+0xb1/0xa20 kernel/locking/mutex.c:621
    [] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341
    [] midisynth_subscribe+0xf7/0x350 sound/core/seq/seq_midi.c:188
    [<     inline     >] subscribe_port sound/core/seq/seq_ports.c:427
    [] check_and_subscribe_port+0x467/0x5c0 sound/core/seq/seq_ports.c:510
    [] snd_seq_port_connect+0x2c9/0x500 sound/core/seq/seq_ports.c:579
    [] snd_seq_ioctl_subscribe_port+0x1d8/0x2b0 sound/core/seq/seq_clientmgr.c:1480
    [] snd_seq_do_ioctl+0x184/0x1e0 sound/core/seq/seq_clientmgr.c:2225
    [] snd_seq_kernel_client_ctl+0xa8/0x110 sound/core/seq/seq_clientmgr.c:2440
    [] snd_seq_oss_midi_open+0x3b4/0x610 sound/core/seq/oss/seq_oss_midi.c:375
    [] snd_seq_oss_synth_setup_midi+0x107/0x4c0 sound/core/seq/oss/seq_oss_synth.c:281
    [] snd_seq_oss_open+0x748/0x8d0 sound/core/seq/oss/seq_oss_init.c:274
    [] odev_open+0x6a/0x90 sound/core/seq/oss/seq_oss.c:138
    [] soundcore_open+0x30f/0x640 sound/sound_core.c:639
    ......

 other info that might help us debug this:

 Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&grp->list_mutex);
                                lock(register_mutex#5);
                                lock(&grp->list_mutex);
   lock(register_mutex#5);

 *** DEADLOCK ***
======================================================

The fix is to simply move the registration parts in
snd_rawmidi_dev_register() to the outside of the register_mutex lock.
The lock is needed only to manage the linked list, and it's not
necessarily to cover the whole initialization process.

Reported-by: Dmitry Vyukov 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: timer: Fix leak in events via snd_timer_user_tinterrupt

2016-08-10T09:49:26+00:00

commit e4ec8cc8039a7063e24204299b462bd1383184a5 upstream.

The stack object “r1” has a total size of 32 bytes. Its field
“event” and “val” both contain 4 bytes padding. These 8 bytes
padding bytes are sent to user without being initialized.

Signed-off-by: Kangjie Lu 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: timer: Fix leak in events via snd_timer_user_ccallback

2016-08-10T09:49:26+00:00

commit 9a47e9cff994f37f7f0dbd9ae23740d0f64f9fe6 upstream.

The stack object “r1” has a total size of 32 bytes. Its field
“event” and “val” both contain 4 bytes padding. These 8 bytes
padding bytes are sent to user without being initialized.

Signed-off-by: Kangjie Lu 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: timer: Fix leak in SNDRV_TIMER_IOCTL_PARAMS

2016-08-10T09:49:26+00:00

commit cec8f96e49d9be372fdb0c3836dcf31ec71e457e upstream.

The stack object “tread” has a total size of 32 bytes. Its field
“event” and “val” both contain 4 bytes padding. These 8 bytes
padding bytes are sent to user without being initialized.

Signed-off-by: Kangjie Lu 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: ctl: Stop notification after disconnection

2016-07-27T16:47:38+00:00

commit f388cdcdd160687c6650833f286b9c89c50960ff upstream.

snd_ctl_remove() has a notification for the removal event.  It's
superfluous when done during the device got disconnected.  Although
the notification itself is mostly harmless, it may potentially be
harmful, and should be suppressed.  Actually some components PCM may
free ctl elements during the disconnect or free callbacks, thus it's
no theoretical issue.

This patch adds the check of card->shutdown flag for avoiding
unnecessary notifications after (or during) the disconnect.

Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: pcm: Free chmap at PCM free callback, too

2016-07-27T16:47:38+00:00

commit a8ff48cb70835f48de5703052760312019afea55 upstream.

The chmap ctls assigned to PCM streams are freed in the PCM disconnect
callback.  However, since the disconnect callback isn't called when
the card gets freed before registering, the chmap ctls may still be
left assigned.  They are eventually freed together with other ctls,
but it may cause an Oops at pcm_chmap_ctl_private_free(), as the
function refers to the assigned PCM stream, while the PCM objects have
been already freed beforehand.

The fix is to free the chmap ctls also at PCM free callback, not only
at PCM disconnect.

Reported-by: Laxminath Kasam 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: timer: Fix negative queue usage by racy accesses

2016-07-27T16:47:38+00:00

commit 3fa6993fef634e05d200d141a85df0b044572364 upstream.

The user timer tu->qused counter may go to a negative value when
multiple concurrent reads are performed since both the check and the
decrement of tu->qused are done in two individual locked contexts.
This results in bogus read outs, and the endless loop in the
user-space side.

The fix is to move the decrement of the tu->qused counter into the
same spinlock context as the zero-check of the counter.

Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman