syzbot


WARNING in as102_dvb_dmx_start_feed

Status: upstream: reported C repro on 2026/03/25 18:11
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+763a11951983705d8ec7@syzkaller.appspotmail.com
First crash: 4d08h, last: 1d11h
Bug presence (1)
Date Name Commit Repro Result
2026/03/25 upstream (ToT) bbeb83d3182a C [report] WARNING in as102_dvb_dmx_start_feed
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 WARNING in as102_dvb_dmx_start_feed origin:upstream -1 C 18 3h52m 3d21h 0/2 upstream: reported C repro on 2026/03/26 05:44
upstream WARNING in as102_dvb_dmx_start_feed media -1 C error 169 26m 3d21h 0/29 upstream: reported C repro on 2026/03/26 05:13
linux-6.1 WARNING in as102_dvb_dmx_start_feed origin:upstream -1 C 10 1h31m 3d17h 0/3 upstream: reported C repro on 2026/03/26 09:14

Sample crash report:
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: CPU: 1 PID: 4547 at kernel/locking/mutex.c:575 __mutex_lock_common+0x195d/0x2400 kernel/locking/mutex.c:-1
Modules linked in:
CPU: 0 PID: 4547 Comm: syz.3.174 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__mutex_lock_common+0x195d/0x2400 kernel/locking/mutex.c:575
Code: 00 48 8d bc 24 e0 00 00 00 0f 85 e3 e7 ff ff 48 c7 c7 80 16 2b 8a 48 c7 c6 c0 16 2b 8a e8 6b 83 ec ff 48 8d bc 24 e0 00 00 00 <0f> 0b e9 c1 e7 ff ff e8 17 87 3b f7 e9 00 fc ff ff 0f 0b e9 40 f0
RSP: 0018:ffffc90005477a60 EFLAGS: 00010246
RAX: 0bcd747f89127d00 RBX: dffffc0000000000 RCX: ffff888076dd3b80
RDX: 0000000000000000 RSI: 0000000080000000 RDI: ffffc90005477b40
RBP: ffffc90005477be8 R08: ffff8880b912795b R09: 1ffff11017224f2b
R10: dffffc0000000000 R11: ffffed1017224f2c R12: 0000000000000000
R13: 1ffff92000a8ef64 R14: ffffffff86ce1d0c R15: 0000000000000000
FS:  000055556d5f4500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdf258a5a08 CR3: 0000000025e34000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_interruptible_nested+0x17/0x20 kernel/locking/mutex.c:765
 as102_dvb_dmx_start_feed+0x6c/0x280 drivers/media/usb/as102/as102_drv.c:139
 dmx_section_feed_start_filtering+0x4f1/0x690 drivers/media/dvb-core/dvb_demux.c:983
 dvb_dmxdev_filter_start+0xc87/0x1090 drivers/media/dvb-core/dmxdev.c:766
 dvb_demux_do_ioctl+0x463/0x530 drivers/media/dvb-core/dmxdev.c:1077
 dvb_usercopy+0x191/0x2b0 drivers/media/dvb-core/dvbdev.c:1017
 dvb_demux_ioctl+0x25/0x30 drivers/media/dvb-core/dmxdev.c:1195
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 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: 0033:0x7fbff7f4c799
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:00007ffe409d2f28 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fbff81c5fa0 RCX: 00007fbff7f4c799
RDX: 0000200000000200 RSI: 00000000403c6f2b RDI: 0000000000000004
RBP: 00007fbff7fe2c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbff81c5fac R14: 00007fbff81c5fa0 R15: 00007fbff81c5fa0
 </TASK>

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/25 19:47 linux-5.15.y 91d48252ad4b 8ee77f7d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in as102_dvb_dmx_start_feed
2026/03/25 18:53 linux-5.15.y 91d48252ad4b 8ee77f7d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in as102_dvb_dmx_start_feed
2026/03/28 15:42 linux-5.15.y 91d48252ad4b b5ceaad2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in as102_dvb_dmx_start_feed
2026/03/28 15:41 linux-5.15.y 91d48252ad4b b5ceaad2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in as102_dvb_dmx_start_feed
2026/03/28 03:40 linux-5.15.y 91d48252ad4b 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in as102_dvb_dmx_start_feed
2026/03/28 03:38 linux-5.15.y 91d48252ad4b 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in as102_dvb_dmx_start_feed
2026/03/26 19:45 linux-5.15.y 91d48252ad4b 766b6434 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in as102_dvb_dmx_start_feed
2026/03/26 19:45 linux-5.15.y 91d48252ad4b 766b6434 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in as102_dvb_dmx_start_feed
2026/03/26 05:17 linux-5.15.y 91d48252ad4b c6143aac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in as102_dvb_dmx_start_feed
2026/03/26 05:17 linux-5.15.y 91d48252ad4b c6143aac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in as102_dvb_dmx_start_feed
2026/03/25 23:50 linux-5.15.y 91d48252ad4b c6143aac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in as102_dvb_dmx_start_feed
2026/03/25 18:10 linux-5.15.y 91d48252ad4b 8ee77f7d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in as102_dvb_dmx_start_feed
* Struck through repros no longer work on HEAD.