syzbot


possible deadlock in ocfs2_xattr_set

Status: upstream: reported on 2024/09/25 09:02
Reported-by: syzbot+c0d46b51c54922dc038f@syzkaller.appspotmail.com
First crash: 3d03h, last: 3d03h
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 possible deadlock in ocfs2_xattr_set 3 13d 14d 0/3 upstream: reported on 2024/09/14 01:11
upstream possible deadlock in ocfs2_xattr_set ocfs2 39 20h20m 18d 0/28 upstream: reported on 2024/09/10 05:07

Sample crash report:
loop3: detected capacity change from 0 to 32768
ocfs2: Mounting device (7,3) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.1.111-syzkaller #0 Not tainted
------------------------------------------------------
syz.3.1949/9628 is trying to acquire lock:
ffff8880599ba648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff8880599ba648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: ocfs2_xattr_set+0xe96/0x1930 fs/ocfs2/xattr.c:3618

but task is already holding lock:
ffff8880599bdc78 (&oi->ip_xattr_sem){++++}-{3:3}, at: ocfs2_xattr_set+0x62f/0x1930 fs/ocfs2/xattr.c:3579

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&oi->ip_xattr_sem){++++}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_read+0xad/0xa30 kernel/locking/rwsem.c:1520
       ocfs2_init_acl+0x398/0x930 fs/ocfs2/acl.c:365
       ocfs2_mknod+0x1f75/0x2e20 fs/ocfs2/namei.c:408
       ocfs2_mkdir+0x1c0/0x4e0 fs/ocfs2/namei.c:655
       vfs_mkdir+0x3b6/0x590 fs/namei.c:4108
       do_mkdirat+0x225/0x360 fs/namei.c:4133
       __do_sys_mkdir fs/namei.c:4153 [inline]
       __se_sys_mkdir fs/namei.c:4151 [inline]
       __x64_sys_mkdir+0x6a/0x80 fs/namei.c:4151
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (jbd2_handle){++++}-{0:0}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       jbd2_journal_lock_updates+0xa6/0x380 fs/jbd2/transaction.c:880
       __ocfs2_flush_truncate_log+0x2ef/0x12a0 fs/ocfs2/alloc.c:6022
       ocfs2_flush_truncate_log+0x4b/0x60 fs/ocfs2/alloc.c:6069
       ocfs2_sync_fs+0x121/0x380 fs/ocfs2/super.c:402
       sync_filesystem+0x1bc/0x220 fs/sync.c:66
       generic_shutdown_super+0x6b/0x340 fs/super.c:474
       kill_block_super+0x7a/0xe0 fs/super.c:1470
       deactivate_locked_super+0xa0/0x110 fs/super.c:332
       cleanup_mnt+0x490/0x520 fs/namespace.c:1186
       task_work_run+0x246/0x300 kernel/task_work.c:203
       resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
       exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
       exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
       __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
       syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
       do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:758 [inline]
       ocfs2_xattr_set+0xe96/0x1930 fs/ocfs2/xattr.c:3618
       __vfs_setxattr+0x3e7/0x420 fs/xattr.c:182
       __vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
       vfs_setxattr+0x21d/0x420 fs/xattr.c:309
       do_setxattr fs/xattr.c:594 [inline]
       setxattr+0x250/0x2b0 fs/xattr.c:617
       path_setxattr+0x1bc/0x2a0 fs/xattr.c:636
       __do_sys_lsetxattr fs/xattr.c:659 [inline]
       __se_sys_lsetxattr fs/xattr.c:655 [inline]
       __x64_sys_lsetxattr+0xb4/0xd0 fs/xattr.c:655
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  &ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5 --> 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(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5);

 *** DEADLOCK ***

3 locks held by syz.3.1949/9628:
 #0: ffff8880270b8460 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
 #1: ffff8880599bdf48 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff8880599bdf48 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: vfs_setxattr+0x1dd/0x420 fs/xattr.c:308
 #2: ffff8880599bdc78 (&oi->ip_xattr_sem){++++}-{3:3}, at: ocfs2_xattr_set+0x62f/0x1930 fs/ocfs2/xattr.c:3579

stack backtrace:
CPU: 1 PID: 9628 Comm: syz.3.1949 Not tainted 6.1.111-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 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+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 down_write+0x36/0x60 kernel/locking/rwsem.c:1573
 inode_lock include/linux/fs.h:758 [inline]
 ocfs2_xattr_set+0xe96/0x1930 fs/ocfs2/xattr.c:3618
 __vfs_setxattr+0x3e7/0x420 fs/xattr.c:182
 __vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
 vfs_setxattr+0x21d/0x420 fs/xattr.c:309
 do_setxattr fs/xattr.c:594 [inline]
 setxattr+0x250/0x2b0 fs/xattr.c:617
 path_setxattr+0x1bc/0x2a0 fs/xattr.c:636
 __do_sys_lsetxattr fs/xattr.c:659 [inline]
 __se_sys_lsetxattr fs/xattr.c:655 [inline]
 __x64_sys_lsetxattr+0xb4/0xd0 fs/xattr.c:655
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f526cd7def9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f526dc16038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007f526cf35f80 RCX: 00007f526cd7def9
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000020000080
RBP: 00007f526cdf0b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f526cf35f80 R15: 00007ffd5c2fdc38
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/25 09:02 linux-6.1.y e526b12bf916 349a68c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in ocfs2_xattr_set
2024/09/25 09:02 linux-6.1.y e526b12bf916 349a68c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in ocfs2_xattr_set
* Struck through repros no longer work on HEAD.