[v6.1] possible deadlock in ocfs2_xattr_ibody_find

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0bc96de781b4 Linux 6.1.148
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1582c3bc580000
kernel config: https://syzkaller.appspot.com/x/.config?x=483f799cd9933afc
dashboard link: https://syzkaller.appspot.com/bug?extid=993cfcc7cd0bb9f3bfd9
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/cd15350f801a/disk-0bc96de7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/789a5d74139d/vmlinux-0bc96de7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a1ef0a7e815a/Image-0bc96de7.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+993cfc...@syzkaller.appspotmail.com

JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.1.148-syzkaller #0 Not tainted
------------------------------------------------------
syz.0.80/4647 is trying to acquire lock:
ffff0000f59d94a0 (&oi->ip_alloc_sem){++++}-{3:3}, at: ocfs2_xattr_ibody_find+0x100/0x668 fs/ocfs2/xattr.c:2693

but task is already holding lock:
ffff0000f59d9538 (&oi->ip_xattr_sem){++++}-{3:3}, at: ocfs2_xattr_set+0x32c/0xe98 fs/ocfs2/xattr.c:3587

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&oi->ip_xattr_sem){++++}-{3:3}:
down_read+0x64/0x304 kernel/locking/rwsem.c:1520
ocfs2_init_acl+0x258/0x5f0 fs/ocfs2/acl.c:365
ocfs2_mknod+0x1168/0x1f18 fs/ocfs2/namei.c:410
ocfs2_create+0x19c/0x4f0 fs/ocfs2/namei.c:674
lookup_open fs/namei.c:3482 [inline]
open_last_lookups fs/namei.c:3550 [inline]
path_openat+0x112c/0x2680 fs/namei.c:3780
do_filp_open+0x174/0x344 fs/namei.c:3810
do_sys_openat2+0x128/0x3d8 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_openat fs/open.c:1350 [inline]
__se_sys_openat fs/open.c:1345 [inline]
__arm64_sys_openat+0x120/0x154 fs/open.c:1345
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x138 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

-> #3 (jbd2_handle){++++}-{0:0}:
start_this_handle+0xfe0/0x122c fs/jbd2/transaction.c:463
jbd2__journal_start+0x288/0x51c fs/jbd2/transaction.c:520
jbd2_journal_start+0x3c/0x4c fs/jbd2/transaction.c:559
ocfs2_start_trans+0x380/0x6c4 fs/ocfs2/journal.c:376
ocfs2_mknod+0xc7c/0x1f18 fs/ocfs2/namei.c:361
ocfs2_create+0x19c/0x4f0 fs/ocfs2/namei.c:674
lookup_open fs/namei.c:3482 [inline]
open_last_lookups fs/namei.c:3550 [inline]
path_openat+0x112c/0x2680 fs/namei.c:3780
do_filp_open+0x174/0x344 fs/namei.c:3810
do_sys_openat2+0x128/0x3d8 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_openat fs/open.c:1350 [inline]
__se_sys_openat fs/open.c:1345 [inline]
__arm64_sys_openat+0x120/0x154 fs/open.c:1345
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x138 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

-> #2 (&journal->j_trans_barrier){.+.+}-{3:3}:
down_read+0x64/0x304 kernel/locking/rwsem.c:1520
ocfs2_start_trans+0x374/0x6c4 fs/ocfs2/journal.c:374
ocfs2_mknod+0xc7c/0x1f18 fs/ocfs2/namei.c:361
ocfs2_create+0x19c/0x4f0 fs/ocfs2/namei.c:674
lookup_open fs/namei.c:3482 [inline]
open_last_lookups fs/namei.c:3550 [inline]
path_openat+0x112c/0x2680 fs/namei.c:3780
do_filp_open+0x174/0x344 fs/namei.c:3810
do_sys_openat2+0x128/0x3d8 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_openat fs/open.c:1350 [inline]
__se_sys_openat fs/open.c:1345 [inline]
__arm64_sys_openat+0x120/0x154 fs/open.c:1345
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x138 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

-> #1 (sb_internal#2){.+.+}-{0:0}:
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1891 [inline]
sb_start_intwrite include/linux/fs.h:2013 [inline]
ocfs2_start_trans+0x20c/0x6c4 fs/ocfs2/journal.c:372
ocfs2_zero_start_ordered_transaction fs/ocfs2/file.c:719 [inline]
ocfs2_write_zero_page fs/ocfs2/file.c:765 [inline]
ocfs2_zero_extend_range fs/ocfs2/file.c:949 [inline]
ocfs2_zero_extend+0x7a4/0x23d4 fs/ocfs2/file.c:994
ocfs2_extend_no_holes+0x1f8/0x424 fs/ocfs2/file.c:1040
ocfs2_extend_file+0x1b4/0x4c4 fs/ocfs2/file.c:1095
ocfs2_setattr+0x848/0x18d4 fs/ocfs2/file.c:1214
notify_change+0xb0c/0xdcc fs/attr.c:499
do_truncate+0x178/0x1f0 fs/open.c:65
do_sys_ftruncate+0x284/0x31c fs/open.c:193
__do_sys_ftruncate fs/open.c:204 [inline]
__se_sys_ftruncate fs/open.c:202 [inline]
__arm64_sys_ftruncate+0x60/0x74 fs/open.c:202
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x138 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

-> #0 (&oi->ip_alloc_sem){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3090 [inline]
check_prevs_add kernel/locking/lockdep.c:3209 [inline]
validate_chain kernel/locking/lockdep.c:3825 [inline]
__lock_acquire+0x293c/0x6544 kernel/locking/lockdep.c:5049
lock_acquire+0x20c/0x644 kernel/locking/lockdep.c:5662
down_read+0x64/0x304 kernel/locking/rwsem.c:1520
ocfs2_xattr_ibody_find+0x100/0x668 fs/ocfs2/xattr.c:2693
ocfs2_xattr_set+0x340/0xe98 fs/ocfs2/xattr.c:3592
ocfs2_set_acl+0x3ec/0x4a0 fs/ocfs2/acl.c:254
ocfs2_iop_set_acl+0x174/0x240 fs/ocfs2/acl.c:285
set_posix_acl fs/posix_acl.c:1160 [inline]
posix_acl_xattr_set+0x2f8/0x398 fs/posix_acl.c:1189
__vfs_removexattr+0x370/0x38c fs/xattr.c:479
__vfs_removexattr_locked+0x1d0/0x208 fs/xattr.c:514
vfs_removexattr+0x80/0x190 fs/xattr.c:536
removexattr fs/xattr.c:878 [inline]
path_removexattr+0x188/0x31c fs/xattr.c:892
__do_sys_removexattr fs/xattr.c:906 [inline]
__se_sys_removexattr fs/xattr.c:903 [inline]
__arm64_sys_removexattr+0x60/0x78 fs/xattr.c:903
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x138 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

other info that might help us debug this:

Chain exists of:
&oi->ip_alloc_sem --> jbd2_handle --> &oi->ip_xattr_sem

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&oi->ip_xattr_sem);
lock(jbd2_handle);
lock(&oi->ip_xattr_sem);
lock(&oi->ip_alloc_sem);

*** DEADLOCK ***

3 locks held by syz.0.80/4647:
#0: ffff0000d2a70460 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:393
#1: ffff0000f59d9808 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#1: ffff0000f59d9808 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: vfs_removexattr+0x6c/0x190 fs/xattr.c:535
#2: ffff0000f59d9538 (&oi->ip_xattr_sem){++++}-{3:3}, at: ocfs2_xattr_set+0x32c/0xe98 fs/ocfs2/xattr.c:3587

stack backtrace:
CPU: 0 PID: 4647 Comm: syz.0.80 Not tainted 6.1.148-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
Call trace:
dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack+0x30/0x40 lib/dump_stack.c:88
dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
dump_stack+0x1c/0x5c lib/dump_stack.c:113
print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2048
check_noncircular+0x240/0x2d4 kernel/locking/lockdep.c:2170
check_prev_add kernel/locking/lockdep.c:3090 [inline]
check_prevs_add kernel/locking/lockdep.c:3209 [inline]
validate_chain kernel/locking/lockdep.c:3825 [inline]
__lock_acquire+0x293c/0x6544 kernel/locking/lockdep.c:5049
lock_acquire+0x20c/0x644 kernel/locking/lockdep.c:5662
down_read+0x64/0x304 kernel/locking/rwsem.c:1520
ocfs2_xattr_ibody_find+0x100/0x668 fs/ocfs2/xattr.c:2693
ocfs2_xattr_set+0x340/0xe98 fs/ocfs2/xattr.c:3592
ocfs2_set_acl+0x3ec/0x4a0 fs/ocfs2/acl.c:254
ocfs2_iop_set_acl+0x174/0x240 fs/ocfs2/acl.c:285
set_posix_acl fs/posix_acl.c:1160 [inline]
posix_acl_xattr_set+0x2f8/0x398 fs/posix_acl.c:1189
__vfs_removexattr+0x370/0x38c fs/xattr.c:479
__vfs_removexattr_locked+0x1d0/0x208 fs/xattr.c:514
vfs_removexattr+0x80/0x190 fs/xattr.c:536
removexattr fs/xattr.c:878 [inline]
path_removexattr+0x188/0x31c fs/xattr.c:892
__do_sys_removexattr fs/xattr.c:906 [inline]
__se_sys_removexattr fs/xattr.c:903 [inline]
__arm64_sys_removexattr+0x60/0x78 fs/xattr.c:903
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x138 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


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[syzbot]

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