syzbot
general protection fault in keyspan_break_ctl
Status:
upstream: reported syz repro on 2026/08/27 18:53
Subsystems:
usb
Labels:
prio:high
[Documentation on labels]
Reported-by: syzbot+473d7477c523b41d4046@syzkaller.appspotmail.com
First crash: 5d16h, last: 5d08h
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Last patch testing requests (1)
Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000013: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000098-0x000000000000009f]
CPU: 2 UID: 0 PID: 6029 Comm: syz.3.20 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:keyspan_break_ctl+0x8e/0xe0 drivers/usb/serial/keyspan.c:608
Code: ff ff ff e8 54 ca 48 fa 83 fb ff 48 b8 00 00 00 00 00 fc ff df 49 8d bc 24 9c 00 00 00 0f 94 c3 48 89 fa 0f b6 db 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1d 41
RSP: 0018:ffffc900035b7cb0 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff87c231ec
RDX: 0000000000000013 RSI: 00000000ffffffff RDI: 000000000000009c
RBP: ffff88802f436000 R08: 0000000000000005 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff888034d39020 R14: ffff888034d390c8 R15: 0000000000000000
FS: 0000555589f16500(0000) GS:ffff8880d5da2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5bac070000 CR3: 00000000584fe000 CR4: 0000000000352ef0
Call Trace:
<TASK>
serial_break+0xcb/0x160 drivers/usb/serial/usb-serial.c:538
send_break drivers/tty/tty_io.c:2458 [inline]
send_break+0x2ec/0x370 drivers/tty/tty_io.c:2441
tty_ioctl+0xa2c/0x1640 drivers/tty/tty_io.c:2733
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5bac19e0d9
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:00007ffd93db7608 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f5bac425fa0 RCX: 00007f5bac19e0d9
RDX: 0000000000000000 RSI: 0000000000005425 RDI: 0000000000000004
RBP: 00007f5bac235024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5bac425fac R14: 00007f5bac425fa0 R15: 00007f5bac425fa0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:keyspan_break_ctl+0x8e/0xe0 drivers/usb/serial/keyspan.c:608
Code: ff ff ff e8 54 ca 48 fa 83 fb ff 48 b8 00 00 00 00 00 fc ff df 49 8d bc 24 9c 00 00 00 0f 94 c3 48 89 fa 0f b6 db 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1d 41
RSP: 0018:ffffc900035b7cb0 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff87c231ec
RDX: 0000000000000013 RSI: 00000000ffffffff RDI: 000000000000009c
RBP: ffff88802f436000 R08: 0000000000000005 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff888034d39020 R14: ffff888034d390c8 R15: 0000000000000000
FS: 0000555589f16500(0000) GS:ffff8880d5da2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5bac070000 CR3: 00000000584fe000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess), 2 bytes skipped:
0: ff ljmp (bad)
1: e8 54 ca 48 fa call 0xfa48ca5a
6: 83 fb ff cmp $0xffffffff,%ebx
9: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
10: fc ff df
13: 49 8d bc 24 9c 00 00 lea 0x9c(%r12),%rdi
1a: 00
1b: 0f 94 c3 sete %bl
1e: 48 89 fa mov %rdi,%rdx
21: 0f b6 db movzbl %bl,%ebx
24: 48 c1 ea 03 shr $0x3,%rdx
* 28: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx <-- trapping instruction
2c: 48 89 f8 mov %rdi,%rax
2f: 83 e0 07 and $0x7,%eax
32: 83 c0 03 add $0x3,%eax
35: 38 d0 cmp %dl,%al
37: 7c 04 jl 0x3d
39: 84 d2 test %dl,%dl
3b: 75 1d jne 0x5a
3d: 41 rex.B
Struck through repros no longer work on HEAD.