UBSAN: array-index-out-of-bounds in snd_dummy_probe

Status: upstream: reported on 2026/08/05 01:16
Reported-by: syzbot+05a64caf8245c0948f40@syzkaller.appspotmail.com
First crash: 4d18h, last: 4d18h
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 UBSAN: array-index-out-of-bounds in snd_dummy_probe 15 syz, C 3 15h36m 4d22h 0/2 upstream: reported C repro on 2026/08/04 21:14
upstream UBSAN: array-index-out-of-bounds in snd_dummy_probe sound prio:normal 15 syz, C 14 5d00h 3d21h 1/29 upstream: reported C repro on 2026/08/05 22:46
linux-5.15 UBSAN: array-index-out-of-bounds in snd_dummy_probe 15 syz, C 3 19h31m 4d23h 0/3 upstream: reported C repro on 2026/08/04 20:34

Sample crash report:
================================================================================
UBSAN: array-index-out-of-bounds in sound/drivers/dummy.c:1036:40
index -1 is out of range for type 'int[32]'
CPU: 1 PID: 4576 Comm: syz.1.24 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e 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+0x12b2/0x18e0 sound/drivers/dummy.c:1036
 platform_probe+0x137/0x1c0 drivers/base/platform.c:1400
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x24a/0xb40 drivers/base/dd.c:638
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804
 device_driver_attach+0xd9/0x1c0 drivers/base/dd.c:1131
 bind_store+0x33b/0x380 drivers/base/bus.c:216
 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x482/0x9a0 fs/read_write.c:584
 ksys_write+0x14d/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7faafed9e019
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:00007faaffc85028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007faaff025fa0 RCX: 00007faafed9e019
RDX: 0000000000000007 RSI: 0000200000000180 RDI: 0000000000000004
RBP: 00007faafee3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007faaff026038 R14: 00007faaff025fa0 R15: 00007ffd4ee28058
 </TASK>
================================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/05 01:15 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan UBSAN: array-index-out-of-bounds in snd_dummy_probe
* Struck through repros no longer work on HEAD.