From: syzbot <syzbot+ea047a32630b1f47da67@syzkaller.appspotmail.com>
To: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
mchehab@kernel.org, syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [media?] WARNING in as102_stream_ctrl
Date: Sun, 16 Aug 2026 20:34:24 -0700 [thread overview]
Message-ID: <6a828140.10853dc7.22f513.0018.GAE@google.com> (raw)
In-Reply-To: <6a7135a9.d35e88fd.de8b.0004.GAE@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: dcb68831eac7 Merge tag 'block-7.2-20260815' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15a356c6580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2ca5f2f2c4197664
dashboard link: https://syzkaller.appspot.com/bug?extid=ea047a32630b1f47da67
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: i386
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=144afa79580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=128fc679580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ce324780f4da/disk-dcb68831.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/54b24f8a899c/vmlinux-dcb68831.xz
kernel image: https://storage.googleapis.com/syzbot-assets/733dcdb8d8dd/bzImage-dcb68831.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ea047a32630b1f47da67@syzkaller.appspotmail.com
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common kernel/locking/mutex.c:625 [inline], CPU#1: syz.2.149/6139
WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550 kernel/locking/mutex.c:821, CPU#1: syz.2.149/6139
Modules linked in:
CPU: 1 UID: 0 PID: 6139 Comm: syz.2.149 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:625 [inline]
RIP: 0010:__mutex_lock+0x12df/0x1550 kernel/locking/mutex.c:821
Code: c2 57 90 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 47 02 00 00 83 3d 45 d0 83 04 00 75 13 48 8d 3d c8 1f 87 04 48 c7 c6 40 f7 ec 8b <67> 48 0f b9 3a 90 e9 75 ee ff ff 90 0f 0b 90 e9 48 f2 ff ff 90 0f
RSP: 0000:ffffc9000381f5c0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff8880321a0000
RDX: 0000000000000000 RSI: ffffffff8becf740 RDI: ffffffff905b11d0
RBP: ffffc9000381f758 R08: ffffffff9057c243 R09: 1ffffffff20af848
R10: dffffc0000000000 R11: fffffbfff20af849 R12: ffff88803476a010
R13: 0000000000000000 R14: 1ffff92000703ecc R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125049000(0063) knlGS:0000000057754480
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f741be8c CR3: 000000007d7a2000 CR4: 00000000003526f0
Call Trace:
<TASK>
as102_stream_ctrl+0x27/0xc0 drivers/media/usb/as102/as102_drv.c:259
dvb_frontend_open+0x7e2/0x1410 drivers/media/dvb-core/dvb_frontend.c:2825
dvb_device_open+0x24f/0x340 drivers/media/dvb-core/dvbdev.c:109
chrdev_open+0x4d9/0x600 fs/char_dev.c:411
do_dentry_open+0x816/0x1380 fs/open.c:947
vfs_open+0x3b/0x340 fs/open.c:1052
do_open fs/namei.c:4700 [inline]
path_openat+0x2e44/0x3830 fs/namei.c:4863
do_file_open+0x23e/0x4a0 fs/namei.c:4892
do_sys_openat2+0x115/0x200 fs/open.c:1368
do_sys_open fs/open.c:1374 [inline]
__do_compat_sys_openat fs/open.c:1436 [inline]
__se_compat_sys_openat fs/open.c:1434 [inline]
__ia32_compat_sys_openat+0x131/0x160 fs/open.c:1434
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
do_int80_emulation+0x19a/0x550 arch/x86/entry/syscall_32.c:172
asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598
RIP: 0023:0xf71374eb
Code: 57 56 53 8b 44 24 14 f6 00 08 75 23 8b 44 24 18 8b 5c 24 1c 8b 4c 24 20 8b 54 24 24 8b 74 24 28 8b 7c 24 2c 8b 6c 24 30 cd 80 <5b> 5e 5f 5d c3 5b 5e 5f 5d e9 f7 a1 ff ff 66 90 66 90 66 90 90 53
RSP: 002b:00000000ff9eefcc EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000ff9ef090
RDX: 0000000000000802 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
----------------
Code disassembly (best guess):
0: c2 57 90 ret $0x9057
3: 48 c1 e8 03 shr $0x3,%rax
7: 0f b6 04 18 movzbl (%rax,%rbx,1),%eax
b: 84 c0 test %al,%al
d: 0f 85 47 02 00 00 jne 0x25a
13: 83 3d 45 d0 83 04 00 cmpl $0x0,0x483d045(%rip) # 0x483d05f
1a: 75 13 jne 0x2f
1c: 48 8d 3d c8 1f 87 04 lea 0x4871fc8(%rip),%rdi # 0x4871feb
23: 48 c7 c6 40 f7 ec 8b mov $0xffffffff8becf740,%rsi
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: 90 nop
30: e9 75 ee ff ff jmp 0xffffeeaa
35: 90 nop
36: 0f 0b ud2
38: 90 nop
39: e9 48 f2 ff ff jmp 0xfffff286
3e: 90 nop
3f: 0f .byte 0xf
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
prev parent reply other threads:[~2026-08-17 3:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-04 0:43 [syzbot] [media?] WARNING in as102_stream_ctrl syzbot
2026-08-11 5:42 ` syzbot
2026-08-17 3:34 ` syzbot [this message]
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