syzbot


possible deadlock in ocfs2_calc_xattr_init

Status: upstream: reported on 2025/07/13 05:28
Reported-by: syzbot+5d1d7d9196ade07c7f4e@syzkaller.appspotmail.com
First crash: 14d, last: 5d03h
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 possible deadlock in ocfs2_calc_xattr_init (2) 4 1 14d 14d 0/3 upstream: reported on 2025/07/12 15:36
upstream possible deadlock in ocfs2_calc_xattr_init ocfs2 4 162 3d05h 296d 0/29 upstream: reported on 2024/10/04 01:35
linux-6.1 possible deadlock in ocfs2_calc_xattr_init 4 6 202d 236d 0/3 auto-obsoleted due to no activity on 2025/04/15 19:53
linux-5.15 possible deadlock in ocfs2_calc_xattr_init 4 14 140d 316d 0/3 auto-obsoleted due to no activity on 2025/06/17 06:29

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.6.99-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.1750/13431 is trying to acquire lock:
ffff88805dc24e38 (&oi->ip_xattr_sem){++++}-{3:3}, at: ocfs2_calc_xattr_init+0x208/0xd80 fs/ocfs2/xattr.c:627

but task is already holding lock:
ffff88805dc209d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
ffff88805dc209d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x165/0x4360 fs/ocfs2/suballoc.c:782

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}:
       down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:804 [inline]
       ocfs2_remove_inode fs/ocfs2/inode.c:655 [inline]
       ocfs2_wipe_inode fs/ocfs2/inode.c:818 [inline]
       ocfs2_delete_inode fs/ocfs2/inode.c:1079 [inline]
       ocfs2_evict_inode+0x1313/0x3e60 fs/ocfs2/inode.c:1216
       evict+0x486/0x870 fs/inode.c:705
       d_delete_notify include/linux/fsnotify.h:269 [inline]
       vfs_rmdir+0x39b/0x4d0 fs/namei.c:4209
       do_rmdir+0x29e/0x5c0 fs/namei.c:4255
       __do_sys_unlinkat fs/namei.c:4433 [inline]
       __se_sys_unlinkat fs/namei.c:4427 [inline]
       __x64_sys_unlinkat+0xc4/0xe0 fs/namei.c:4427
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #2 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]){+.+.}-{3:3}:
       down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:804 [inline]
       ocfs2_del_inode_from_orphan+0x135/0x740 fs/ocfs2/namei.c:2716
       ocfs2_dio_end_io_write fs/ocfs2/aops.c:2333 [inline]
       ocfs2_dio_end_io+0x47b/0x10f0 fs/ocfs2/aops.c:2431
       dio_complete+0x254/0x710 fs/direct-io.c:282
       __blockdev_direct_IO+0x2dc8/0x3420 fs/direct-io.c:1308
       ocfs2_direct_IO+0x240/0x2b0 fs/ocfs2/aops.c:2468
       generic_file_direct_write+0x1d4/0x3e0 mm/filemap.c:3941
       __generic_file_write_iter+0x11b/0x230 mm/filemap.c:4097
       ocfs2_file_write_iter+0x1582/0x1d00 fs/ocfs2/file.c:2468
       do_iter_readv_writev fs/read_write.c:-1 [inline]
       do_iter_write+0x79a/0xc70 fs/read_write.c:860
       iter_file_splice_write+0x66f/0xc50 fs/splice.c:736
       do_splice_from fs/splice.c:933 [inline]
       direct_splice_actor+0xe8/0x130 fs/splice.c:1142
       splice_direct_to_actor+0x2f0/0x870 fs/splice.c:1088
       do_splice_direct+0x1b7/0x2c0 fs/splice.c:1194
       do_sendfile+0x5dc/0xf70 fs/read_write.c:1254
       __do_sys_sendfile64 fs/read_write.c:1322 [inline]
       __se_sys_sendfile64+0x13f/0x190 fs/read_write.c:1308
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}:
       down_write+0x97/0x1f0 kernel/locking/rwsem.c:1573
       ocfs2_try_remove_refcount_tree+0xb7/0x320 fs/ocfs2/refcounttree.c:932
       ocfs2_truncate_file+0xd84/0x13a0 fs/ocfs2/file.c:521
       ocfs2_setattr+0x150d/0x1b20 fs/ocfs2/file.c:1211
       notify_change+0xb0d/0xe10 fs/attr.c:499
       do_truncate+0x19b/0x220 fs/open.c:66
       handle_truncate fs/namei.c:3291 [inline]
       do_open fs/namei.c:3636 [inline]
       path_openat+0x298c/0x3190 fs/namei.c:3789
       do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
       do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
       do_sys_open fs/open.c:1434 [inline]
       __do_sys_creat fs/open.c:1512 [inline]
       __se_sys_creat fs/open.c:1506 [inline]
       __x64_sys_creat+0x90/0xb0 fs/open.c:1506
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&oi->ip_xattr_sem){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
       lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
       down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520
       ocfs2_calc_xattr_init+0x208/0xd80 fs/ocfs2/xattr.c:627
       ocfs2_mknod+0xc57/0x20f0 fs/ocfs2/namei.c:330
       ocfs2_mkdir+0x196/0x410 fs/ocfs2/namei.c:657
       vfs_mkdir+0x296/0x440 fs/namei.c:4113
       do_mkdirat+0x1d4/0x440 fs/namei.c:4136
       __do_sys_mkdirat fs/namei.c:4151 [inline]
       __se_sys_mkdirat fs/namei.c:4149 [inline]
       __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4149
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  &oi->ip_xattr_sem --> &ocfs2_sysfile_lock_key[args->fi_sysfile_type] --> &ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4);
                               lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]);
                               lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4);
  rlock(&oi->ip_xattr_sem);

 *** DEADLOCK ***

3 locks held by syz.2.1750/13431:
 #0: ffff88805561e418 (sb_writers#26){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:403
 #1: ffff88805dc25118 (&type->i_mutex_dir_key#16/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
 #1: ffff88805dc25118 (&type->i_mutex_dir_key#16/1){+.+.}-{3:3}, at: filename_create+0x1f6/0x460 fs/namei.c:3882
 #2: ffff88805dc209d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #2: ffff88805dc209d8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: ocfs2_reserve_suballoc_bits+0x165/0x4360 fs/ocfs2/suballoc.c:782

stack backtrace:
CPU: 0 PID: 13431 Comm: syz.2.1750 Not tainted 6.6.99-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 check_noncircular+0x2bd/0x3c0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520
 ocfs2_calc_xattr_init+0x208/0xd80 fs/ocfs2/xattr.c:627
 ocfs2_mknod+0xc57/0x20f0 fs/ocfs2/namei.c:330
 ocfs2_mkdir+0x196/0x410 fs/ocfs2/namei.c:657
 vfs_mkdir+0x296/0x440 fs/namei.c:4113
 do_mkdirat+0x1d4/0x440 fs/namei.c:4136
 __do_sys_mkdirat fs/namei.c:4151 [inline]
 __se_sys_mkdirat fs/namei.c:4149 [inline]
 __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4149
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f880338d217
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 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:00007f88031fee68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f88031feef0 RCX: 00007f880338d217
RDX: 00000000000001ff RSI: 00002000000000c0 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000200000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000000c0
R13: 00007f88031feeb0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/22 11:11 linux-6.6.y d96eb99e2f0e 1555463b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in ocfs2_calc_xattr_init
2025/07/13 05:27 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in ocfs2_calc_xattr_init
* Struck through repros no longer work on HEAD.