syzbot
BUG: unable to handle kernel paging request in gs_close
Status:
moderation: reported on 2026/08/05 01:42
Subsystems:
usb
Labels:
prio:low
[Documentation on labels]
Reported-by: syzbot+97aa71f55869d71bc94a@syzkaller.appspotmail.com
First crash: 16d, last: 2d14h
Sample crash report:
fail_dump lib/fault-inject.c:73 [inline]
should_fail_ex+0x41c/0x590 lib/fault-inject.c:174
should_failslab+0xc4/0x120 mm/failslab.c:46
slab_pre_alloc_hook mm/slub.c:4539 [inline]
slab_alloc_node mm/slub.c:4897 [inline]
__do_kmalloc_node mm/slub.c:5333 [inline]
__kmalloc_node_noprof+0x10c/0x6d8 mm/slub.c:5346
_kmalloc_array_node_noprof include/linux/slab.h:1294 [inline]
__kfifo_alloc_node+0x10c/0x208 lib/kfifo.c:44
__kfifo_alloc include/linux/kfifo.h:932 [inline]
gs_open+0x144/0x514 drivers/usb/gadget/function/u_serial.c:636
tty_open+0x404/0x89c drivers/tty/tty_io.c:2137
chrdev_open+0x398/0x3e8 fs/char_dev.c:411
do_dentry_open+0x5c4/0xfc0 fs/open.c:947
vfs_open+0x44/0x2dc fs/open.c:1052
do_open fs/namei.c:4700 [inline]
path_openat+0x21fc/0x2a60 fs/namei.c:4863
do_file_open+0x1c8/0x2e8 fs/namei.c:4892
do_sys_openat2+0x114/0x1e8 fs/open.c:1368
do_sys_open+0xb0/0xe0 fs/open.c:1374
__do_sys_openat fs/open.c:1390 [inline]
__se_sys_openat fs/open.c:1385 [inline]
__arm64_sys_openat+0xa8/0xc4 fs/open.c:1385
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:758
el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:777
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590
Unable to handle kernel paging request at virtual address dfff800000000074
KASAN: null-ptr-deref in range [0x00000000000003a0-0x00000000000003a7]
Mem abort info:
ESR = 0x0000000096000005
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x05: level 1 translation fault
Data abort info:
ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0
[dfff800000000074] address between user and kernel address ranges
Internal error: Oops: 0000000096000005 [#1] SMP
Modules linked in:
CPU: 0 UID: 0 PID: 7402 Comm: syz.3.667 Not tainted syzkaller #0 PREEMPT
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
pstate: 234000c5 (nzCv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : kasan_byte_accessible+0xc/0x1c mm/kasan/generic.c:210
lr : __kasan_check_byte+0x20/0x54 mm/kasan/common.c:573
sp : ffff800095667300
x29: ffff800095667300 x28: ffff800088b3a000 x27: ffff0000c9fed7c0
x26: 1ded8000869306f0 x25: 0000000000000000 x24: 0000000000000001
x23: 0000000000000000 x22: 00000000000003a0 x21: 00000000000003a0
x20: 0000000000000000 x19: ffff8000869306f0 x18: 1fffe00034bb7428
x17: 70202c31206c6176 x16: 0000000000000001 x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000000
x11: ffff800080156070 x10: 0000000000000003 x9 : dfff800000000000
x8 : 0000000000000074 x7 : 0000000000000000 x6 : ffff800083655754
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000000 x1 : ffff8000869306f0 x0 : 00000000000003a0
Call trace:
kasan_mem_to_shadow include/linux/kasan.h:65 [inline] (P)
kasan_byte_accessible+0xc/0x1c mm/kasan/generic.c:210 (P)
kasan_check_byte include/linux/kasan.h:402 [inline]
lock_acquire+0xa4/0x364 kernel/locking/lockdep.c:5842
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock_irq+0x58/0x70 kernel/locking/spinlock.c:174
spin_lock_irq include/linux/spinlock.h:372 [inline]
gs_close+0xac/0x65c drivers/usb/gadget/function/u_serial.c:698
tty_release+0x2c4/0xffc drivers/tty/tty_io.c:1745
tty_open+0x46c/0x89c drivers/tty/tty_io.c:2146
chrdev_open+0x398/0x3e8 fs/char_dev.c:411
do_dentry_open+0x5c4/0xfc0 fs/open.c:947
vfs_open+0x44/0x2dc fs/open.c:1052
do_open fs/namei.c:4700 [inline]
path_openat+0x21fc/0x2a60 fs/namei.c:4863
do_file_open+0x1c8/0x2e8 fs/namei.c:4892
do_sys_openat2+0x114/0x1e8 fs/open.c:1368
do_sys_open+0xb0/0xe0 fs/open.c:1374
__do_sys_openat fs/open.c:1390 [inline]
__se_sys_openat fs/open.c:1385 [inline]
__arm64_sys_openat+0xa8/0xc4 fs/open.c:1385
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:758
el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:777
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590
Code: 17ffffec d343fc08 d2d00009 f2fbffe9 (38696908)
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
0: 17ffffec b 0xffffffffffffffb0
4: d343fc08 lsr x8, x0, #3
8: d2d00009 mov x9, #0x800000000000 // #140737488355328
c: f2fbffe9 movk x9, #0xdfff, lsl #48
* 10: 38696908 ldrb w8, [x8, x9] <-- trapping instruction
* Struck through repros no longer work on HEAD.