[v5.15] possible deadlock in iterate_dir (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9465fef4ae35 Linux 5.15.153
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=166c9f0d180000
kernel config: https://syzkaller.appspot.com/x/.config?x=74ff83133fa97f6c
dashboard link: https://syzkaller.appspot.com/bug?extid=b2fce515df44d2d0384d
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/3c82fda40b43/disk-9465fef4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ec13893dc103/vmlinux-9465fef4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7b44910e5283/Image-9465fef4.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b2fce5...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
5.15.153-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.0/5205 is trying to acquire lock:
ffff0000e8630090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27

but task is already holding lock:
ffff0000d4fc8460 (sb_writers#19){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2492 [inline]
ffff0000d4fc8460 (sb_writers#19){.+.+}-{0:0}, at: iterate_dir+0x400/0x4e4 fs/readdir.c:70

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sb_writers#19){.+.+}-{0:0}:
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1787 [inline]
sb_start_write+0xf0/0x3ac include/linux/fs.h:1857
mnt_want_write_file+0x64/0x1e8 fs/namespace.c:421
reiserfs_ioctl+0x188/0x4b8 fs/reiserfs/ioctl.c:103
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

-> #0 (&sbi->lock){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain kernel/locking/lockdep.c:3788 [inline]
__lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012
lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623
__mutex_lock_common+0x194/0x2154 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27
reiserfs_dirty_inode+0xe4/0x204 fs/reiserfs/super.c:704
__mark_inode_dirty+0x2b0/0x10f4 fs/fs-writeback.c:2464
generic_update_time fs/inode.c:1817 [inline]
inode_update_time fs/inode.c:1830 [inline]
touch_atime+0x4d0/0xa4c fs/inode.c:1902
file_accessed include/linux/fs.h:2492 [inline]
iterate_dir+0x400/0x4e4 fs/readdir.c:70
__do_sys_getdents64 fs/readdir.c:369 [inline]
__se_sys_getdents64 fs/readdir.c:354 [inline]
__arm64_sys_getdents64+0x1c4/0x4c4 fs/readdir.c:354
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(sb_writers#19);
lock(&sbi->lock);
lock(sb_writers#19);
lock(&sbi->lock);

*** DEADLOCK ***

3 locks held by syz-executor.0/5205:
#0: ffff0000dbb400f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x128/0x170 fs/file.c:1088
#1: ffff0000e968a400 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: iterate_dir+0x108/0x4e4 fs/readdir.c:55
#2: ffff0000d4fc8460 (sb_writers#19){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2492 [inline]
#2: ffff0000d4fc8460 (sb_writers#19){.+.+}-{0:0}, at: iterate_dir+0x400/0x4e4 fs/readdir.c:70

stack backtrace:
CPU: 0 PID: 5205 Comm: syz-executor.0 Not tainted 5.15.153-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call trace:
dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
dump_stack+0x1c/0x58 lib/dump_stack.c:113
print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2011
check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2133
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain kernel/locking/lockdep.c:3788 [inline]
__lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012
lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623
__mutex_lock_common+0x194/0x2154 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27
reiserfs_dirty_inode+0xe4/0x204 fs/reiserfs/super.c:704
__mark_inode_dirty+0x2b0/0x10f4 fs/fs-writeback.c:2464
generic_update_time fs/inode.c:1817 [inline]
inode_update_time fs/inode.c:1830 [inline]
touch_atime+0x4d0/0xa4c fs/inode.c:1902
file_accessed include/linux/fs.h:2492 [inline]
iterate_dir+0x400/0x4e4 fs/readdir.c:70
__do_sys_getdents64 fs/readdir.c:369 [inline]
__se_sys_getdents64 fs/readdir.c:354 [inline]
__arm64_sys_getdents64+0x1c4/0x4c4 fs/readdir.c:354
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 9465fef4ae35 Linux 5.15.153
git tree: linux-5.15.y

console output: https://syzkaller.appspot.com/x/log.txt?x=16601321180000

kernel config: https://syzkaller.appspot.com/x/.config?x=74ff83133fa97f6c
dashboard link: https://syzkaller.appspot.com/bug?extid=b2fce515df44d2d0384d
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=108e268d180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11765fb5180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/3c82fda40b43/disk-9465fef4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ec13893dc103/vmlinux-9465fef4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7b44910e5283/Image-9465fef4.gz.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/43adaa7b8772/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b2fce5...@syzkaller.appspotmail.com

REISERFS (device loop0): Using tea hash to sort names
REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.

======================================================
WARNING: possible circular locking dependency detected
5.15.153-syzkaller #0 Not tainted
------------------------------------------------------

syz-executor153/3982 is trying to acquire lock:
ffff0000d9f77090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27

but task is already holding lock:

ffff0000da140460 (sb_writers#8){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2492 [inline]
ffff0000da140460 (sb_writers#8){.+.+}-{0:0}, at: iterate_dir+0x400/0x4e4 fs/readdir.c:70

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sb_writers#8){.+.+}-{0:0}:

lock(sb_writers#8);
lock(&sbi->lock);
lock(sb_writers#8);

lock(&sbi->lock);

*** DEADLOCK ***

3 locks held by syz-executor153/3982:
#0: ffff0000dbcbe5f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x128/0x170 fs/file.c:1088
#1: ffff0000df0b02e0 (&type->i_mutex_dir_key#6){++++}-{3:3}, at: iterate_dir+0x108/0x4e4 fs/readdir.c:55
#2: ffff0000da140460 (sb_writers#8){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2492 [inline]
#2: ffff0000da140460 (sb_writers#8){.+.+}-{0:0}, at: iterate_dir+0x400/0x4e4 fs/readdir.c:70

stack backtrace:
CPU: 0 PID: 3982 Comm: syz-executor153 Not tainted 5.15.153-syzkaller #0

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
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