From: syzbot <syzbot+df9e891bf8ea586f846b@syzkaller.appspotmail.com>
To: kartikey406@gmail.com, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in ep_open
Date: Thu, 30 Jul 2026 22:42:02 -0700 [thread overview]
Message-ID: <6a6c35aa.77639fcc.3d4fd0.001c.GAE@google.com> (raw)
In-Reply-To: <20260731042637.9137-1-kartikey406@gmail.com>
Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
BUG: unable to handle kernel paging request in ep_open
Unable to handle kernel paging request at virtual address dfff800000000003
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
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
[dfff800000000003] address between user and kernel address ranges
Internal error: Oops: 0000000096000005 [#1] SMP
Modules linked in:
CPU: 0 UID: 0 PID: 5115 Comm: syz-executor Not tainted syzkaller #0 PREEMPT
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
pstate: 234000c5 (nzCv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : kasan_byte_accessible+0x10/0x20 mm/kasan/generic.c:210
lr : __kasan_check_byte+0x20/0x54 mm/kasan/common.c:573
sp : ffff800092f37660
x29: ffff800092f37660 x28: ffff800088b0a000 x27: ffff0000c79d57c0
x26: a6d980008690513c x25: 0000000000000000 x24: 0000000000000001
x23: 0000000000000000 x22: 0000000000000018 x21: 0000000000000018
x20: 0000000000000000 x19: ffff80008690513c x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
x14: 00000000ffff8000 x13: 0000000000000001 x12: 0000000000000000
x11: ffff800080156ee8 x10: 0000000000000003 x9 : dfff800000000000
x8 : 0000000000000003 x7 : 0000000000000000 x6 : ffff8000836dc930
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000000 x1 : ffff80008690513c x0 : 0000000000000018
Call trace:
kasan_mem_to_shadow include/linux/kasan.h:65 [inline] (P)
kasan_byte_accessible+0x10/0x20 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]
ep_open+0x70/0x2ec drivers/usb/gadget/legacy/inode.c:824
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+0xa0/0xbc 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:736
el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
Code: d503245f d343fc08 d2d00009 f2fbffe9 (38696908)
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
0: d503245f bti c
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
Tested on:
commit: 365f9c7a Merge branches 'for-next/core' and 'for-next/..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=174c8c9e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=72c97575381cec47
dashboard link: https://syzkaller.appspot.com/bug?extid=df9e891bf8ea586f846b
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: arm64
patch: https://syzkaller.appspot.com/x/patch.diff?x=1176caea580000
next parent reply other threads:[~2026-07-31 5:42 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20260731042637.9137-1-kartikey406@gmail.com>
2026-07-31 5:42 ` syzbot [this message]
[not found] <20260731114022.18295-1-kartikey406@gmail.com>
2026-07-31 16:21 ` syzbot
[not found] <20260731080941.13394-1-kartikey406@gmail.com>
2026-07-31 9:08 ` syzbot
[not found] <20260731044451.10817-1-kartikey406@gmail.com>
2026-07-31 6:59 ` syzbot
2026-07-31 1:28 syzbot
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