Hello,
syzbot found the following issue on:
HEAD commit: 3330a8d33e08 Linux 5.15.201
git tree: linux-5.15.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=17691fb2580000
kernel config:
https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link:
https://syzkaller.appspot.com/bug?extid=d8a78093d7b0bb080e67
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image:
https://storage.googleapis.com/syzbot-assets/b65fe19af112/disk-3330a8d3.raw.xz
vmlinux:
https://storage.googleapis.com/syzbot-assets/351948519a0d/vmlinux-3330a8d3.xz
kernel image:
https://storage.googleapis.com/syzbot-assets/a3b3f8477595/bzImage-3330a8d3.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+d8a780...@syzkaller.appspotmail.com
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 PID: 6978 Comm: syz.2.451 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:su3000_i2c_transfer+0x1a5/0xe70 drivers/media/usb/dvb-usb/dw2102.c:737
Code: 4c 89 f8 48 c1 e8 03 49 bc 00 00 00 00 00 fc ff df 42 80 3c 20 00 74 08 4c 89 ff e8 65 ce 2c fb 49 8b 1f 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 01 08 00 00 0f b6 1b 48 8b 44 24 30 42
RSP: 0018:ffffc900059dfac8 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000000010 RCX: 0000000000000003
RDX: ffffffff86915f7d RSI: ffffffff8d072550 RDI: 0000000000001900
RBP: 0000000000000000 R08: ffff88802191bb80 R09: 0000000000000002
R10: 0000000000001a00 R11: 0000000000000002 R12: dffffc0000000000
R13: 1ffff1100e7b8e98 R14: 0000000000000002 R15: ffff888073dc74c8
FS: 00007fb8a61576c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff149e06000 CR3: 000000007ad23000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__i2c_transfer+0x880/0x20b0 drivers/i2c/i2c-core-base.c:-1
i2c_transfer+0x25d/0x3a0 drivers/i2c/i2c-core-base.c:2330
i2cdev_ioctl_rdwr+0x3dc/0x6d0 drivers/i2c/i2c-dev.c:297
i2cdev_ioctl+0x610/0x7b0 drivers/i2c/i2c-dev.c:458
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: 0033:0x7fb8a7efd629
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:00007fb8a6157028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb8a8176fa0 RCX: 00007fb8a7efd629
RDX: 00002000000001c0 RSI: 0000000000000707 RDI: 0000000000000005
RBP: 00007fb8a7f93b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb8a8177038 R14: 00007fb8a8176fa0 R15: 00007fffe6444bc8
</TASK>
Modules linked in:
---[ end trace 5734c278a3f97563 ]---
RIP: 0010:su3000_i2c_transfer+0x1a5/0xe70 drivers/media/usb/dvb-usb/dw2102.c:737
Code: 4c 89 f8 48 c1 e8 03 49 bc 00 00 00 00 00 fc ff df 42 80 3c 20 00 74 08 4c 89 ff e8 65 ce 2c fb 49 8b 1f 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 01 08 00 00 0f b6 1b 48 8b 44 24 30 42
RSP: 0018:ffffc900059dfac8 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000000010 RCX: 0000000000000003
RDX: ffffffff86915f7d RSI: ffffffff8d072550 RDI: 0000000000001900
RBP: 0000000000000000 R08: ffff88802191bb80 R09: 0000000000000002
R10: 0000000000001a00 R11: 0000000000000002 R12: dffffc0000000000
R13: 1ffff1100e7b8e98 R14: 0000000000000002 R15: ffff888073dc74c8
FS: 00007fb8a61576c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8170880000 CR3: 000000007ad23000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 4c 89 f8 mov %r15,%rax
3: 48 c1 e8 03 shr $0x3,%rax
7: 49 bc 00 00 00 00 00 movabs $0xdffffc0000000000,%r12
e: fc ff df
11: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1)
16: 74 08 je 0x20
18: 4c 89 ff mov %r15,%rdi
1b: e8 65 ce 2c fb call 0xfb2cce85
20: 49 8b 1f mov (%r15),%rbx
23: 48 89 d8 mov %rbx,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax <-- trapping instruction
2f: 84 c0 test %al,%al
31: 0f 85 01 08 00 00 jne 0x838
37: 0f b6 1b movzbl (%rbx),%ebx
3a: 48 8b 44 24 30 mov 0x30(%rsp),%rax
3f: 42 rex.X
---
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