possible deadlock in ocfs2_xattr_set

[sanan....@gmail.com]

Good day, dear maintainers,

We found a bug using a modified version of syzkaller.

Kernel Branch: 7.0-rc1
Kernel Config: <https://drive.google.com/open?id=1mAp3gxor4yGtL0ZArdrc1E7ufSn4T841>
Unfortunately, we don't have any reproducer for this bug yet.
Thank you!

Best regards,
Sanan Hasanov

======================================================
WARNING: possible circular locking dependency detected
7.0.0-rc1 #1 Tainted: G L
------------------------------------------------------
syz.2.3024/27235 is trying to acquire lock:
ffff88804960df40 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
ffff88804960df40 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_xattr_set+0xb12/0x1220 fs/ocfs2/xattr.c:3653

but task is already holding lock:
ffff888062436ab8 (&oi->ip_xattr_sem){++++}-{4:4}, at: ocfs2_xattr_set+0x42d/0x1220 fs/ocfs2/xattr.c:3614

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&oi->ip_xattr_sem){++++}-{4:4}:
down_read+0x47/0x2e0 kernel/locking/rwsem.c:1537
ocfs2_init_acl+0x2f7/0x7a0 fs/ocfs2/acl.c:367
ocfs2_mknod+0x1327/0x20c0 fs/ocfs2/namei.c:414
ocfs2_mkdir+0x181/0x470 fs/ocfs2/namei.c:660
vfs_mkdir+0x408/0x620 fs/namei.c:5233
filename_mkdirat+0x27b/0x500 fs/namei.c:5266
__do_sys_mkdir fs/namei.c:5293 [inline]
__se_sys_mkdir+0x34/0x150 fs/namei.c:5290
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x160/0xfc0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x4b/0x53

-> #2 (&journal->j_trans_barrier){.+.+}-{4:4}:
down_read+0x47/0x2e0 kernel/locking/rwsem.c:1537
ocfs2_start_trans+0x36a/0x6d0 fs/ocfs2/journal.c:369
ocfs2_mknod+0xe97/0x20c0 fs/ocfs2/namei.c:365
vfs_mknod+0x43d/0x600 fs/namei.c:5092
filename_mknodat+0x3bf/0x640 fs/namei.c:-1
__do_sys_mknodat fs/namei.c:5173 [inline]
__se_sys_mknodat+0x3b/0x150 fs/namei.c:5169
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x160/0xfc0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x4b/0x53

-> #1 (sb_internal#3){.+.+}-{0:0}:
percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_intwrite include/linux/fs/super.h:177 [inline]
ocfs2_start_trans+0x26b/0x6d0 fs/ocfs2/journal.c:367
ocfs2_remove_btree_range+0x7e2/0x1480 fs/ocfs2/alloc.c:5760
ocfs2_commit_truncate+0xbb4/0x22f0 fs/ocfs2/alloc.c:7374
ocfs2_truncate_for_delete fs/ocfs2/inode.c:701 [inline]
ocfs2_wipe_inode fs/ocfs2/inode.c:868 [inline]
ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
ocfs2_evict_inode+0x1111/0x4260 fs/ocfs2/inode.c:1299
evict+0x5ed/0xad0 fs/inode.c:846
filename_unlinkat+0x42d/0x5e0 fs/namei.c:5544
__do_sys_unlink fs/namei.c:5575 [inline]
__se_sys_unlink+0x2e/0x140 fs/namei.c:5572
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x160/0xfc0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x4b/0x53

-> #0 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x159d/0x2ce0 kernel/locking/lockdep.c:5237
lock_acquire+0xf1/0x2e0 kernel/locking/lockdep.c:5868
down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590
inode_lock include/linux/fs.h:1028 [inline]
ocfs2_xattr_set+0xb12/0x1220 fs/ocfs2/xattr.c:3653
ocfs2_set_acl+0x701/0x7b0 fs/ocfs2/acl.c:255
ocfs2_iop_set_acl+0x1aa/0x2a0 fs/ocfs2/acl.c:287
set_posix_acl fs/posix_acl.c:955 [inline]
vfs_set_acl+0x8f9/0xbf0 fs/posix_acl.c:1134
do_set_acl+0xf6/0x180 fs/posix_acl.c:1279
do_setxattr fs/xattr.c:633 [inline]
filename_setxattr+0x2f4/0x610 fs/xattr.c:664
path_setxattrat+0x356/0x3a0 fs/xattr.c:708
__do_sys_lsetxattr fs/xattr.c:749 [inline]
__se_sys_lsetxattr fs/xattr.c:745 [inline]
__x64_sys_lsetxattr+0xbf/0xd0 fs/xattr.c:745
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x160/0xfc0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x4b/0x53

other info that might help us debug this:

Chain exists of:
&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE] --> &journal->j_trans_barrier --> &oi->ip_xattr_sem

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&oi->ip_xattr_sem);
lock(&journal->j_trans_barrier);
lock(&oi->ip_xattr_sem);
lock(&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]);

*** DEADLOCK ***

3 locks held by syz.2.3024/27235:
#0: ffff8880637a2420 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff888062436d80 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#1: ffff888062436d80 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: vfs_set_acl+0x3af/0xbf0 fs/posix_acl.c:1115
#2: ffff888062436ab8 (&oi->ip_xattr_sem){++++}-{4:4}, at: ocfs2_xattr_set+0x42d/0x1220 fs/ocfs2/xattr.c:3614

stack backtrace:
CPU: 0 UID: 0 PID: 27235 Comm: syz.2.3024 Tainted: G L 7.0.0-rc1 #1 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_circular_bug+0x2dd/0x2f0 kernel/locking/lockdep.c:2043
check_noncircular+0x129/0x150 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x159d/0x2ce0 kernel/locking/lockdep.c:5237
lock_acquire+0xf1/0x2e0 kernel/locking/lockdep.c:5868
down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590
inode_lock include/linux/fs.h:1028 [inline]
ocfs2_xattr_set+0xb12/0x1220 fs/ocfs2/xattr.c:3653
ocfs2_set_acl+0x701/0x7b0 fs/ocfs2/acl.c:255
ocfs2_iop_set_acl+0x1aa/0x2a0 fs/ocfs2/acl.c:287
set_posix_acl fs/posix_acl.c:955 [inline]
vfs_set_acl+0x8f9/0xbf0 fs/posix_acl.c:1134
do_set_acl+0xf6/0x180 fs/posix_acl.c:1279
do_setxattr fs/xattr.c:633 [inline]
filename_setxattr+0x2f4/0x610 fs/xattr.c:664
path_setxattrat+0x356/0x3a0 fs/xattr.c:708
__do_sys_lsetxattr fs/xattr.c:749 [inline]
__se_sys_lsetxattr fs/xattr.c:745 [inline]
__x64_sys_lsetxattr+0xbf/0xd0 fs/xattr.c:745
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x160/0xfc0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f23845a3b6d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f23827f6018 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007f2384815fa0 RCX: 00007f23845a3b6d
RDX: 00002000000000c0 RSI: 0000200000000440 RDI: 0000200000000400
RBP: 00007f2384647c3e R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000005c R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2384816038 R14: 00007f2384815fa0 R15: 00007fff10fbf4c0
</TASK>

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