syzbot
BUG: unable to handle kernel NULL pointer dereference in snd_ctl_led_get
Status:
upstream: reported C repro on 2026/08/27 09:47
Subsystems:
sound
Labels:
prio:low
[Documentation on labels]
Reported-by: syzbot+b7fe2760ea6f1ee44b4d@syzkaller.appspotmail.com
First crash: 42d, last: 15h23m
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Last patch testing requests (3)
Sample crash report:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 0 P4D 0
Oops: Oops: 0010 [#1] SMP KASAN NOPTI
CPU: 2 UID: 0 PID: 6042 Comm: syz-executor129 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc900034b7948 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88802e2ff400 RCX: 0000000000000000
RDX: 1ffff11005c5fe8c RSI: ffffffff9bda4620 RDI: ffff88802e2ff400
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff9bda4620 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff90b73bc8 R14: ffff88802e2ff400 R15: ffffffff90b73bc8
FS: 000055555669f400(0000) GS:ffff8880d5da2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000027234000 CR4: 0000000000352ef0
Call Trace:
<TASK>
snd_ctl_led_get+0x231/0x430 sound/core/control_led.c:122
snd_ctl_led_set_state+0x5c1/0x7f0 sound/core/control_led.c:168
snd_ctl_led_notify+0x15b/0x1e0 sound/core/control_led.c:239
snd_ctl_led_set_id sound/core/control_led.c:268 [inline]
set_led_id+0xb0f/0xe80 sound/core/control_led.c:557
dev_attr_store+0x58/0x80 drivers/base/core.c:2509
sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6af/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa7e64de2b7
Code: 48 89 fa 4c 89 df e8 98 1d 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffe15525110 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055555669f400 RCX: 00007fa7e64de2b7
RDX: 0000000000000002 RSI: 00007ffe155251a0 RDI: 0000000000000004
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe155251a0
R13: 00007fa7e6517024 R14: 00007fa7e6541cc0 R15: 0000000000000002
</TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc900034b7948 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88802e2ff400 RCX: 0000000000000000
RDX: 1ffff11005c5fe8c RSI: ffffffff9bda4620 RDI: ffff88802e2ff400
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff9bda4620 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff90b73bc8 R14: ffff88802e2ff400 R15: ffffffff90b73bc8
FS: 000055555669f400(0000) GS:ffff8880d5da2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000027234000 CR4: 0000000000352ef0
* Struck through repros no longer work on HEAD.