syzbot
UBSAN: array-index-out-of-bounds in snd_dummy_probe
Status:
upstream: reported C repro on 2026/08/04 20:34
Reported-by: syzbot+e39c875bcc8f123c3dc9@syzkaller.appspotmail.com
First crash: 5d02h, last: 22h02m
Sample crash report:
================================================================================
UBSAN: array-index-out-of-bounds in sound/drivers/dummy.c:1028:40
index -1 is out of range for type 'int[32]'
CPU: 1 PID: 4345 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
ubsan_epilogue+0xa/0x30 lib/ubsan.c:151
__ubsan_handle_out_of_bounds+0xdf/0xf0 lib/ubsan.c:282
snd_dummy_probe+0x1257/0x1890 sound/drivers/dummy.c:1028
platform_probe+0x137/0x1c0 drivers/base/platform.c:1391
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x276/0xc70 drivers/base/dd.c:595
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775
device_driver_attach+0xdc/0x1d0 drivers/base/dd.c:1096
bind_store+0x33b/0x380 drivers/base/bus.c:216
kernfs_fop_write_iter+0x3a8/0x500 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2173 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x748/0xd70 fs/read_write.c:594
ksys_write+0x153/0x260 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f00d42f00d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe50f65588 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f00d4577fa0 RCX: 00007f00d42f00d9
RDX: 0000000000000007 RSI: 0000200000000180 RDI: 0000000000000004
RBP: 00007f00d4387024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f00d4577fac R14: 00007f00d4577fa0 R15: 00007f00d4577fa0
</TASK>
================================================================================
* Struck through repros no longer work on HEAD.