[syzbot] WARNING: locking bug in open_xa_dir

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 85413d1e802e Merge branch 'for-next/fixes' into for-kernelci
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=128a2817080000
kernel config: https://syzkaller.appspot.com/x/.config?x=57b9bfeca947ab90
dashboard link: https://syzkaller.appspot.com/bug?extid=ca91a9d7f091db185abe
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ca91a9...@syzkaller.appspotmail.com

------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(1)
WARNING: CPU: 1 PID: 10629 at kernel/locking/lockdep.c:231 check_wait_context kernel/locking/lockdep.c:4727 [inline]
WARNING: CPU: 1 PID: 10629 at kernel/locking/lockdep.c:231 __lock_acquire+0x2b0/0x30a4 kernel/locking/lockdep.c:5003
Modules linked in:
CPU: 1 PID: 10629 Comm: syz-executor.1 Not tainted 6.0.0-rc3-syzkaller-16800-g85413d1e802e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : check_wait_context kernel/locking/lockdep.c:4727 [inline]
pc : __lock_acquire+0x2b0/0x30a4 kernel/locking/lockdep.c:5003
lr : hlock_class kernel/locking/lockdep.c:231 [inline]
lr : check_wait_context kernel/locking/lockdep.c:4727 [inline]
lr : __lock_acquire+0x298/0x30a4 kernel/locking/lockdep.c:5003
sp : ffff800013a3b570
x29: ffff800013a3b650 x28: 0000000000000000 x27: ffff0000ff2ccf80
x26: ffff0000fc51f250 x25: ffff0000ff2cd9b0 x24: 0000000000000080
x23: 0000000000000000 x22: 0000000000000001 x21: 0000000000000000
x20: 0000000000000000 x19: aaaaaaaaaaa78f9e x18: 0000000000000041
x17: 0000000000000000 x16: ffff80000dbb8658 x15: ffff0000ff2ccf80
x14: 0000000000000000 x13: 0000000000000012 x12: ffff80000d65f8d0
x11: ff808000081c39d0 x10: ffff80000dd7a698 x9 : 2d75630c93b4cc00
x8 : 0000000000000000 x7 : 4e5241575f534b43 x6 : ffff8000081c0d80
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000001 x1 : 0000000100000001 x0 : 0000000000000016
Call trace:
check_wait_context kernel/locking/lockdep.c:4727 [inline]
__lock_acquire+0x2b0/0x30a4 kernel/locking/lockdep.c:5003
lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0x70/0x9c kernel/locking/spinlock.c:170
rwsem_down_write_slowpath+0xdc/0x520 kernel/locking/rwsem.c:1128
__down_write_common kernel/locking/rwsem.c:1297 [inline]
__down_write kernel/locking/rwsem.c:1306 [inline]
down_write_nested+0x90/0xc4 kernel/locking/rwsem.c:1663
inode_lock_nested include/linux/fs.h:791 [inline]
open_xa_root fs/reiserfs/xattr.c:127 [inline]
open_xa_dir+0x5c/0x2a8 fs/reiserfs/xattr.c:152
xattr_lookup+0x34/0x198 fs/reiserfs/xattr.c:395
reiserfs_xattr_get+0x8c/0x680 fs/reiserfs/xattr.c:677
reiserfs_get_acl+0x84/0x1ac fs/reiserfs/xattr_acl.c:214
get_acl+0x104/0x330 fs/posix_acl.c:152
check_acl+0x40/0x168 fs/namei.c:306
acl_permission_check fs/namei.c:351 [inline]
generic_permission+0x270/0x32c fs/namei.c:404
reiserfs_permission+0x4c/0x6c fs/reiserfs/xattr.c:954
do_inode_permission fs/namei.c:458 [inline]
inode_permission+0x128/0x244 fs/namei.c:525
may_open+0x1e4/0x2bc fs/namei.c:3185
do_open fs/namei.c:3555 [inline]
path_openat+0xdd0/0x11c4 fs/namei.c:3691
do_filp_open+0xdc/0x1b8 fs/namei.c:3718
do_sys_openat2+0xb8/0x22c fs/open.c:1311
do_sys_open fs/open.c:1327 [inline]
__do_sys_openat fs/open.c:1343 [inline]
__se_sys_openat fs/open.c:1338 [inline]
__arm64_sys_openat+0xb0/0xe0 fs/open.c:1338
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x48/0x154 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:624
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:642
el0t_64_sync+0x18c/0x190
irq event stamp: 8960
hardirqs last enabled at (8959): [<ffff800008163d98>] raw_spin_rq_unlock_irq kernel/sched/sched.h:1367 [inline]
hardirqs last enabled at (8959): [<ffff800008163d98>] finish_lock_switch+0x94/0xe8 kernel/sched/core.c:4942
hardirqs last disabled at (8960): [<ffff80000c01388c>] __raw_spin_lock_irq include/linux/spinlock_api_smp.h:117 [inline]
hardirqs last disabled at (8960): [<ffff80000c01388c>] _raw_spin_lock_irq+0x34/0x9c kernel/locking/spinlock.c:170
softirqs last enabled at (8942): [<ffff80000801c1f4>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (8940): [<ffff80000801c1c0>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---
Unable to handle kernel NULL pointer dereference at virtual address 00000000000000b8
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
user pgtable: 4k pages, 48-bit VAs, pgdp=000000013ce6a000
[00000000000000b8] pgd=080000013c54e003, p4d=080000013c54e003, pud=080000013b6f2003, pmd=0000000000000000
Internal error: Oops: 96000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 10629 Comm: syz-executor.1 Tainted: G W 6.0.0-rc3-syzkaller-16800-g85413d1e802e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : check_wait_context kernel/locking/lockdep.c:4727 [inline]
pc : __lock_acquire+0x2d0/0x30a4 kernel/locking/lockdep.c:5003
lr : hlock_class kernel/locking/lockdep.c:231 [inline]
lr : check_wait_context kernel/locking/lockdep.c:4727 [inline]
lr : __lock_acquire+0x298/0x30a4 kernel/locking/lockdep.c:5003
sp : ffff800013a3b570
x29: ffff800013a3b650 x28: 0000000000000000 x27: ffff0000ff2ccf80
x26: ffff0000fc51f250 x25: ffff0000ff2cd9b0 x24: 0000000000000080
x23: 0000000000000000 x22: 0000000000000001 x21: 0000000000000000
x20: 0000000000000000 x19: aaaaaaaaaaa78f9e x18: 0000000000000041
x17: 0000000000000000 x16: ffff80000dbb8658 x15: ffff0000ff2ccf80
x14: 0000000000000000 x13: 0000000000000012 x12: ffff80000d65f8d0
x11: ff808000081c39d0 x10: ffff80000dd7a698 x9 : 00000000000c0f9e
x8 : 0000000000000000 x7 : 4e5241575f534b43 x6 : ffff8000081c0d80
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000001 x1 : 0000000100000001 x0 : 0000000000000016
Call trace:
hlock_class kernel/locking/lockdep.c:222 [inline]
check_wait_context kernel/locking/lockdep.c:4728 [inline]
__lock_acquire+0x2d0/0x30a4 kernel/locking/lockdep.c:5003
lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0x70/0x9c kernel/locking/spinlock.c:170
rwsem_down_write_slowpath+0xdc/0x520 kernel/locking/rwsem.c:1128
__down_write_common kernel/locking/rwsem.c:1297 [inline]
__down_write kernel/locking/rwsem.c:1306 [inline]
down_write_nested+0x90/0xc4 kernel/locking/rwsem.c:1663
inode_lock_nested include/linux/fs.h:791 [inline]
open_xa_root fs/reiserfs/xattr.c:127 [inline]
open_xa_dir+0x5c/0x2a8 fs/reiserfs/xattr.c:152
xattr_lookup+0x34/0x198 fs/reiserfs/xattr.c:395
reiserfs_xattr_get+0x8c/0x680 fs/reiserfs/xattr.c:677
reiserfs_get_acl+0x84/0x1ac fs/reiserfs/xattr_acl.c:214
get_acl+0x104/0x330 fs/posix_acl.c:152
check_acl+0x40/0x168 fs/namei.c:306
acl_permission_check fs/namei.c:351 [inline]
generic_permission+0x270/0x32c fs/namei.c:404
reiserfs_permission+0x4c/0x6c fs/reiserfs/xattr.c:954
do_inode_permission fs/namei.c:458 [inline]
inode_permission+0x128/0x244 fs/namei.c:525
may_open+0x1e4/0x2bc fs/namei.c:3185
do_open fs/namei.c:3555 [inline]
path_openat+0xdd0/0x11c4 fs/namei.c:3691
do_filp_open+0xdc/0x1b8 fs/namei.c:3718
do_sys_openat2+0xb8/0x22c fs/open.c:1311
do_sys_open fs/open.c:1327 [inline]
__do_sys_openat fs/open.c:1343 [inline]
__se_sys_openat fs/open.c:1338 [inline]
__arm64_sys_openat+0xb0/0xe0 fs/open.c:1338
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x48/0x154 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:624
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:642
el0t_64_sync+0x18c/0x190
Code: b002deea 91196210 911a614a b9400329 (3942e114)
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
0: b002deea adrp x10, 0x5bdd000
4: 91196210 add x16, x16, #0x658
8: 911a614a add x10, x10, #0x698
c: b9400329 ldr w9, [x25]
* 10: 3942e114 ldrb w20, [x8, #184] <-- trapping instruction


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.