syzbot
BUG: unable to handle kernel paging request in keyspan_break_ctl
Status:
upstream: reported C repro on 2026/10/11 16:26
Reported-by: syzbot+40bb1b64d79808a9a165@syzkaller.appspotmail.com
First crash: 1d10h, last: 1d08h
Sample crash report:
Unable to handle kernel paging request at virtual address dfff800000000013
KASAN: null-ptr-deref in range [0x0000000000000098-0x000000000000009f]
Mem abort info:
ESR = 0x0000000096000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x06: level 2 translation fault
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
[dfff800000000013] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4544 Comm: syz.1.22 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026
pstate: 02400005 (nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : keyspan_break_ctl+0x80/0xcc drivers/usb/serial/keyspan.c:-1
lr : keyspan_break_ctl+0x6c/0xcc drivers/usb/serial/keyspan.c:609
sp : ffff800021ee7c20
x29: ffff800021ee7c20 x28: 0000000000000000 x27: 1fffe0001bf9f000
x26: dfff800000000000 x25: ffff80000db3de60 x24: 1fffe0001ba7e203
x23: ffff0000dd3f1018 x22: 0000000000000000 x21: dfff800000000000
x20: 0000000000000000 x19: ffff0000ddabe000 x18: 1fffe00033c1c97e
x17: ffff80001641d000 x16: ffff8000082dd38c x15: 0000000040000000
x14: 0000000000000010 x13: 1ffff000043dcf28 x12: 0000000000000000
x11: ff0080000db9c100 x10: 0000000000000007 x9 : 0000000000000013
x8 : 000000000000009c x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000040 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000006 x1 : 0000000000000000 x0 : 00000000ffffffff
Call trace:
keyspan_break_ctl+0x80/0xcc drivers/usb/serial/keyspan.c:-1
serial_break+0xb0/0xf8 drivers/usb/serial/usb-serial.c:541
send_break+0x1d4/0x288 drivers/tty/tty_io.c:2484
tty_ioctl+0xc3c/0xd88 drivers/tty/tty_io.c:-1
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: 3100069f d343fd09 1200090a 11000d4a (38f56929)
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
0: 3100069f cmn w20, #0x1
4: d343fd09 lsr x9, x8, #3
8: 1200090a and w10, w8, #0x7
c: 11000d4a add w10, w10, #0x3
* 10: 38f56929 ldrsb w9, [x9, x21] <-- trapping instruction
* Struck through repros no longer work on HEAD.