<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git, branch v4.4.21</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v4.4.21</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v4.4.21'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2016-09-15T06:29:29+00:00</updated>
<entry>
<title>Linux 4.4.21</title>
<updated>2016-09-15T06:29:29+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2016-09-15T06:29:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=1d074db69c46d62ce82b331c2080e2fcb710bf4a'/>
<id>urn:sha1:1d074db69c46d62ce82b331c2080e2fcb710bf4a</id>
<content type='text'>
</content>
</entry>
<entry>
<title>lib/mpi: mpi_write_sgl(): fix skipping of leading zero limbs</title>
<updated>2016-09-15T06:27:54+00:00</updated>
<author>
<name>Nicolai Stange</name>
<email>nicstange@gmail.com</email>
</author>
<published>2016-03-22T12:12:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=11c27e850d90372d79c1337be299923b5fb353e8'/>
<id>urn:sha1:11c27e850d90372d79c1337be299923b5fb353e8</id>
<content type='text'>
commit f2d1362ff7d266b3d2b1c764d6c2ef4a3b457f23 upstream.

Currently, if the number of leading zeros is greater than fits into a
complete limb, mpi_write_sgl() skips them by iterating over them limb-wise.

However, it fails to adjust its internal leading zeros tracking variable,
lzeros, accordingly: it does a

  p -= sizeof(alimb);
  continue;

which should really have been a

  lzeros -= sizeof(alimb);
  continue;

Since lzeros never decreases if its initial value &gt;= sizeof(alimb), nothing
gets copied by mpi_write_sgl() in that case.

Instead of skipping the high order zero limbs within the loop as shown
above, fix the issue by adjusting the copying loop's bounds.

Fixes: 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers")
Signed-off-by: Nicolai Stange &lt;nicstange@gmail.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>regulator: anatop: allow regulator to be in bypass mode</title>
<updated>2016-09-15T06:27:54+00:00</updated>
<author>
<name>Mika Båtsman</name>
<email>mbatsman@mvista.com</email>
</author>
<published>2016-06-17T10:31:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=3838b04f6d5868f5ec5ee52ce1391b6253c6ce16'/>
<id>urn:sha1:3838b04f6d5868f5ec5ee52ce1391b6253c6ce16</id>
<content type='text'>
commit 8a092e682f20f193f2070dba2ea1904e95814126 upstream.

Bypass support was added in commit d38018f2019c ("regulator: anatop: Add
bypass support to digital LDOs"). A check for valid voltage selectors was
added in commit da0607c8df5c ("regulator: anatop: Fail on invalid voltage
selector") but it also discards all regulators that are in bypass mode. Add
check for the bypass setting. Errors below were seen on a Variscite mx6
board.

anatop_regulator 20c8000.anatop:regulator-vddcore@140: Failed to read a valid default voltage selector.
anatop_regulator: probe of 20c8000.anatop:regulator-vddcore@140 failed with error -22
anatop_regulator 20c8000.anatop:regulator-vddsoc@140: Failed to read a valid default voltage selector.
anatop_regulator: probe of 20c8000.anatop:regulator-vddsoc@140 failed with error -22

Fixes: da0607c8df5c ("regulator: anatop: Fail on invalid voltage selector")
Signed-off-by: Mika Båtsman &lt;mbatsman@mvista.com&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>hwrng: exynos - Disable runtime PM on probe failure</title>
<updated>2016-09-15T06:27:54+00:00</updated>
<author>
<name>Krzysztof Kozlowski</name>
<email>k.kozlowski@samsung.com</email>
</author>
<published>2016-03-14T00:07:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=390bddc4a36d2ce015a9d78d8624e575cbac9cd3'/>
<id>urn:sha1:390bddc4a36d2ce015a9d78d8624e575cbac9cd3</id>
<content type='text'>
commit 48a61e1e2af8020f11a2b8f8dc878144477623c6 upstream.

Add proper error path (for disabling runtime PM) when registering of
hwrng fails.

Fixes: b329669ea0b5 ("hwrng: exynos - Add support for Exynos random number generator")
Signed-off-by: Krzysztof Kozlowski &lt;k.kozlowski@samsung.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>cpufreq: Fix GOV_LIMITS handling for the userspace governor</title>
<updated>2016-09-15T06:27:54+00:00</updated>
<author>
<name>Sai Gurrappadi</name>
<email>sgurrappadi@nvidia.com</email>
</author>
<published>2016-04-29T21:44:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=aaac8cab2f92aa235f6f79e8cff52bf11c0fbf1d'/>
<id>urn:sha1:aaac8cab2f92aa235f6f79e8cff52bf11c0fbf1d</id>
<content type='text'>
commit e43e94c1eda76dabd686ddf6f7825f54d747b310 upstream.

Currently, the userspace governor only updates frequency on GOV_LIMITS
if policy-&gt;cur falls outside policy-&gt;{min/max}. However, it is also
necessary to update current frequency on GOV_LIMITS to match the user
requested value if it can be achieved within the new policy-&gt;{max/min}.

This was previously the behaviour in the governor until commit d1922f0
("cpufreq: Simplify userspace governor") which incorrectly assumed that
policy-&gt;cur == user requested frequency via scaling_setspeed. This won't
be true if the user requested frequency falls outside policy-&gt;{min/max}.
Ex: a temporary thermal cap throttled the user requested frequency.

Fix this by storing the user requested frequency in a seperate variable.
The governor will then try to achieve this request on every GOV_LIMITS
change.

Fixes: d1922f02562f (cpufreq: Simplify userspace governor)
Signed-off-by: Sai Gurrappadi &lt;sgurrappadi@nvidia.com&gt;
Acked-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>metag: Fix atomic_*_return inline asm constraints</title>
<updated>2016-09-15T06:27:54+00:00</updated>
<author>
<name>James Hogan</name>
<email>james.hogan@imgtec.com</email>
</author>
<published>2016-05-03T08:11:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=73e6305cf0f89ee66abe522a75eb614212b1c8a2'/>
<id>urn:sha1:73e6305cf0f89ee66abe522a75eb614212b1c8a2</id>
<content type='text'>
commit 096a8b6d5e7ab9f8ca3d2474b3ca6a1fe79e0371 upstream.

The argument i of atomic_*_return() operations is given to inline asm
with the "bd" constraint, which means "An Op2 register where Op1 is a
data unit register and the instruction supports O2R", however Op1 is
constrained by "da" which allows an address unit register to be used.

Fix the constraint to use "br", meaning "An Op2 register and the
instruction supports O2R", i.e. not requiring Op1 to be a data unit
register.

Fixes: d6dfe2509da9 ("locking,arch,metag: Fold atomic_ops")
Signed-off-by: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: linux-metag@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>scsi: fix upper bounds check of sense key in scsi_sense_key_string()</title>
<updated>2016-09-15T06:27:54+00:00</updated>
<author>
<name>Tyrel Datwyler</name>
<email>tyreld@linux.vnet.ibm.com</email>
</author>
<published>2016-08-12T22:20:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=6f0caecda50f411841d9791e1fe54c30d33969b7'/>
<id>urn:sha1:6f0caecda50f411841d9791e1fe54c30d33969b7</id>
<content type='text'>
commit a87eeb900dbb9f8202f96604d56e47e67c936b9d upstream.

Commit 655ee63cf371 ("scsi constants: command, sense key + additional
sense string") added a "Completed" sense string with key 0xF to
snstext[], but failed to updated the upper bounds check of the sense key
in scsi_sense_key_string().

Fixes: 655ee63cf371 ("[SCSI] scsi constants: command, sense key + additional sense strings")
Signed-off-by: Tyrel Datwyler &lt;tyreld@linux.vnet.ibm.com&gt;
Reviewed-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Signed-off-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>ALSA: timer: fix NULL pointer dereference on memory allocation failure</title>
<updated>2016-09-15T06:27:54+00:00</updated>
<author>
<name>Vegard Nossum</name>
<email>vegard.nossum@oracle.com</email>
</author>
<published>2016-08-28T22:33:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=f5b004e4edb87ea4c0a72a72191f33d372d08251'/>
<id>urn:sha1:f5b004e4edb87ea4c0a72a72191f33d372d08251</id>
<content type='text'>
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:[&lt;ffffffff82c8ba07&gt;]  [&lt;ffffffff82c8ba07&gt;] 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:
     [&lt;ffffffff82c81ab1&gt;] snd_timer_start1+0x331/0x670
     [&lt;ffffffff82c85bfd&gt;] snd_timer_start+0x5d/0xa0
     [&lt;ffffffff82c8795e&gt;] snd_timer_user_ioctl+0x88e/0x2830
     [&lt;ffffffff8159f3a0&gt;] ? __follow_pte.isra.49+0x430/0x430
     [&lt;ffffffff82c870d0&gt;] ? snd_timer_pause+0x80/0x80
     [&lt;ffffffff815a26fa&gt;] ? do_wp_page+0x3aa/0x1c90
     [&lt;ffffffff8132762f&gt;] ? put_prev_entity+0x108f/0x21a0
     [&lt;ffffffff82c870d0&gt;] ? snd_timer_pause+0x80/0x80
     [&lt;ffffffff816b0733&gt;] do_vfs_ioctl+0x193/0x1050
     [&lt;ffffffff813510af&gt;] ? cpuacct_account_field+0x12f/0x1a0
     [&lt;ffffffff816b05a0&gt;] ? ioctl_preallocate+0x200/0x200
     [&lt;ffffffff81002f2f&gt;] ? syscall_trace_enter+0x3cf/0xdb0
     [&lt;ffffffff815045ba&gt;] ? __context_tracking_exit.part.4+0x9a/0x1e0
     [&lt;ffffffff81002b60&gt;] ? exit_to_usermode_loop+0x190/0x190
     [&lt;ffffffff82001a97&gt;] ? check_preemption_disabled+0x37/0x1e0
     [&lt;ffffffff81d93889&gt;] ? security_file_ioctl+0x89/0xb0
     [&lt;ffffffff816b167f&gt;] SyS_ioctl+0x8f/0xc0
     [&lt;ffffffff816b15f0&gt;] ? do_vfs_ioctl+0x1050/0x1050
     [&lt;ffffffff81005524&gt;] do_syscall_64+0x1c4/0x4e0
     [&lt;ffffffff83c32b2a&gt;] 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 &lt;0f&gt; b6 04 02 84 c0 74 04 84 c0 7e 65 80 7b 48 00 74 0e e8 52 46
    RIP  [&lt;ffffffff82c8ba07&gt;] snd_hrtimer_start+0x77/0x100
     RSP &lt;ffff8801120c7a60&gt;
    ---[ 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-&gt;private_data = NULL
        - snd_timer_open()
           - snd_hrtimer_open()
              - kzalloc() fails; t-&gt;private_data is still NULL

    ioctl(SNDRV_TIMER_IOCTL_START)
     - snd_timer_user_start()
	- snd_timer_start()
	   - snd_timer_start1()
	      - snd_hrtimer_start()
		- t-&gt;private_data == NULL // boom

Signed-off-by: Vegard Nossum &lt;vegard.nossum@oracle.com&gt;
Signed-off-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE</title>
<updated>2016-09-15T06:27:54+00:00</updated>
<author>
<name>Vegard Nossum</name>
<email>vegard.nossum@oracle.com</email>
</author>
<published>2016-08-28T22:33:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=6fd91313bfcfd44cebcb2a55dbeeb606ee3cd710'/>
<id>urn:sha1:6fd91313bfcfd44cebcb2a55dbeeb606ee3cd710</id>
<content type='text'>
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:[&lt;ffffffff82c8bd9a&gt;]  [&lt;ffffffff82c8bd9a&gt;] 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:
     &lt;IRQ&gt;
     [&lt;ffffffff813abce7&gt;] __hrtimer_run_queues+0x347/0xa00
     [&lt;ffffffff82c8bbc0&gt;] ? snd_hrtimer_close+0x130/0x130
     [&lt;ffffffff813ab9a0&gt;] ? retrigger_next_event+0x1b0/0x1b0
     [&lt;ffffffff813ae1a6&gt;] ? hrtimer_interrupt+0x136/0x4b0
     [&lt;ffffffff813ae220&gt;] hrtimer_interrupt+0x1b0/0x4b0
     [&lt;ffffffff8120f91e&gt;] local_apic_timer_interrupt+0x6e/0xf0
     [&lt;ffffffff81227ad3&gt;] ? kvm_guest_apic_eoi_write+0x13/0xc0
     [&lt;ffffffff83c35086&gt;] smp_apic_timer_interrupt+0x76/0xa0
     [&lt;ffffffff83c3416c&gt;] apic_timer_interrupt+0x8c/0xa0
     &lt;EOI&gt;
     [&lt;ffffffff83c3239c&gt;] ? _raw_spin_unlock_irqrestore+0x2c/0x60
     [&lt;ffffffff82c8185d&gt;] snd_timer_start1+0xdd/0x670
     [&lt;ffffffff82c87015&gt;] snd_timer_continue+0x45/0x80
     [&lt;ffffffff82c88100&gt;] snd_timer_user_ioctl+0x1030/0x2830
     [&lt;ffffffff8159f3a0&gt;] ? __follow_pte.isra.49+0x430/0x430
     [&lt;ffffffff82c870d0&gt;] ? snd_timer_pause+0x80/0x80
     [&lt;ffffffff815a26fa&gt;] ? do_wp_page+0x3aa/0x1c90
     [&lt;ffffffff815aa4f8&gt;] ? handle_mm_fault+0xbc8/0x27f0
     [&lt;ffffffff815a9930&gt;] ? __pmd_alloc+0x370/0x370
     [&lt;ffffffff82c870d0&gt;] ? snd_timer_pause+0x80/0x80
     [&lt;ffffffff816b0733&gt;] do_vfs_ioctl+0x193/0x1050
     [&lt;ffffffff816b05a0&gt;] ? ioctl_preallocate+0x200/0x200
     [&lt;ffffffff81002f2f&gt;] ? syscall_trace_enter+0x3cf/0xdb0
     [&lt;ffffffff815045ba&gt;] ? __context_tracking_exit.part.4+0x9a/0x1e0
     [&lt;ffffffff81002b60&gt;] ? exit_to_usermode_loop+0x190/0x190
     [&lt;ffffffff82001a97&gt;] ? check_preemption_disabled+0x37/0x1e0
     [&lt;ffffffff81d93889&gt;] ? security_file_ioctl+0x89/0xb0
     [&lt;ffffffff816b167f&gt;] SyS_ioctl+0x8f/0xc0
     [&lt;ffffffff816b15f0&gt;] ? do_vfs_ioctl+0x1050/0x1050
     [&lt;ffffffff81005524&gt;] do_syscall_64+0x1c4/0x4e0
     [&lt;ffffffff83c32b2a&gt;] 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 &lt;48&gt; f7 f9 49 01 c7 e8 cb 42 7b fe 48 8b 55 d0 48 b8 00 00 00 00
    RIP  [&lt;ffffffff82c8bd9a&gt;] snd_hrtimer_callback+0x1da/0x3f0
     RSP &lt;ffff88011aa87da8&gt;
    ---[ end trace 6aa380f756a21074 ]---

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

Signed-off-by: Vegard Nossum &lt;vegard.nossum@oracle.com&gt;
Signed-off-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>ALSA: timer: fix NULL pointer dereference in read()/ioctl() race</title>
<updated>2016-09-15T06:27:54+00:00</updated>
<author>
<name>Vegard Nossum</name>
<email>vegard.nossum@oracle.com</email>
</author>
<published>2016-08-28T08:13:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=6664ad65f31ecb35f4f7d8208036b5dbc7640740'/>
<id>urn:sha1:6664ad65f31ecb35f4f7d8208036b5dbc7640740</id>
<content type='text'>
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:
     [&lt;ffffffff81f9f141&gt;] dump_stack+0x83/0xb2
     [&lt;ffffffff8161fe3f&gt;] kasan_report_error+0x41f/0x4c0
     [&lt;ffffffff8161ff74&gt;] kasan_report+0x34/0x40
     [&lt;ffffffff82c84b54&gt;] ? snd_timer_user_read+0x554/0x790
     [&lt;ffffffff8161e79e&gt;] check_memory_region+0x13e/0x1a0
     [&lt;ffffffff8161e9c1&gt;] kasan_check_read+0x11/0x20
     [&lt;ffffffff82c84b54&gt;] snd_timer_user_read+0x554/0x790
     [&lt;ffffffff82c84600&gt;] ? snd_timer_user_info_compat.isra.5+0x2b0/0x2b0
     [&lt;ffffffff817d0831&gt;] ? proc_fault_inject_write+0x1c1/0x250
     [&lt;ffffffff817d0670&gt;] ? next_tgid+0x2a0/0x2a0
     [&lt;ffffffff8127c278&gt;] ? do_group_exit+0x108/0x330
     [&lt;ffffffff8174653a&gt;] ? fsnotify+0x72a/0xca0
     [&lt;ffffffff81674dfe&gt;] __vfs_read+0x10e/0x550
     [&lt;ffffffff82c84600&gt;] ? snd_timer_user_info_compat.isra.5+0x2b0/0x2b0
     [&lt;ffffffff81674cf0&gt;] ? do_sendfile+0xc50/0xc50
     [&lt;ffffffff81745e10&gt;] ? __fsnotify_update_child_dentry_flags+0x60/0x60
     [&lt;ffffffff8143fec6&gt;] ? kcov_ioctl+0x56/0x190
     [&lt;ffffffff81e5ada2&gt;] ? common_file_perm+0x2e2/0x380
     [&lt;ffffffff81746b0e&gt;] ? __fsnotify_parent+0x5e/0x2b0
     [&lt;ffffffff81d93536&gt;] ? security_file_permission+0x86/0x1e0
     [&lt;ffffffff816728f5&gt;] ? rw_verify_area+0xe5/0x2b0
     [&lt;ffffffff81675355&gt;] vfs_read+0x115/0x330
     [&lt;ffffffff81676371&gt;] SyS_read+0xd1/0x1a0
     [&lt;ffffffff816762a0&gt;] ? vfs_write+0x4b0/0x4b0
     [&lt;ffffffff82001c2c&gt;] ? __this_cpu_preempt_check+0x1c/0x20
     [&lt;ffffffff8150455a&gt;] ? __context_tracking_exit.part.4+0x3a/0x1e0
     [&lt;ffffffff816762a0&gt;] ? vfs_write+0x4b0/0x4b0
     [&lt;ffffffff81005524&gt;] do_syscall_64+0x1c4/0x4e0
     [&lt;ffffffff810052fc&gt;] ? syscall_return_slowpath+0x16c/0x1d0
     [&lt;ffffffff83c3276a&gt;] 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-&gt;queue/tu-&gt;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-&gt;queue/to-&gt;tqueue which means read()
   could potentially see (and dereference) the freed pointer

We can fix both by taking the ioctl_lock mutex when dereferencing
-&gt;queue/-&gt;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-&gt;qhead pointing outside the buffer if the size is
changed concurrently using SNDRV_TIMER_IOCTL_PARAMS.

Signed-off-by: Vegard Nossum &lt;vegard.nossum@oracle.com&gt;
Signed-off-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
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