syzbot


possible deadlock in ocfs2_xattr_ibody_find

Status: upstream: reported on 2025/08/19 23:24
Reported-by: syzbot+993cfcc7cd0bb9f3bfd9@syzkaller.appspotmail.com
First crash: 10d, last: 8d00h
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in ocfs2_xattr_ibody_find ocfs2 4 C inconclusive done 49 118d 271d 0/29 auto-obsoleted due to no activity on 2025/07/12 21:15
upstream possible deadlock in ocfs2_xattr_ibody_find (2) ocfs2 4 37 10h12m 8d02h 0/29 upstream: reported on 2025/08/22 08:08

Sample crash report:
JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,3) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.1.148-syzkaller #0 Not tainted
------------------------------------------------------
syz.3.112/4947 is trying to acquire lock:
ffff0000f5658660 (&oi->ip_alloc_sem){++++}-{3:3}, at: ocfs2_xattr_ibody_find+0x100/0x668 fs/ocfs2/xattr.c:2693

but task is already holding lock:
ffff0000f56586f8 (&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#3){.+.+}-{0:0}:
       __lock_release kernel/locking/lockdep.c:5376 [inline]
       lock_release+0x308/0x910 kernel/locking/lockdep.c:5682
       up_write+0x48/0x5c0 kernel/locking/rwsem.c:1625
       inode_unlock include/linux/fs.h:763 [inline]
       ocfs2_free_ac_resource fs/ocfs2/suballoc.c:126 [inline]
       ocfs2_free_alloc_context+0x94/0x188 fs/ocfs2/suballoc.c:140
       ocfs2_write_begin_nolock+0x3a1c/0x3ab4 fs/ocfs2/aops.c:1825
       ocfs2_write_begin+0x1b4/0x30c fs/ocfs2/aops.c:1904
       generic_perform_write+0x230/0x4b0 mm/filemap.c:3846
       __generic_file_write_iter+0x168/0x37c mm/filemap.c:3974
       ocfs2_file_write_iter+0x1300/0x1bf4 fs/ocfs2/file.c:2469
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x5ac/0x7c4 fs/read_write.c:584
       ksys_pwrite64 fs/read_write.c:699 [inline]
       __do_sys_pwrite64 fs/read_write.c:709 [inline]
       __se_sys_pwrite64 fs/read_write.c:706 [inline]
       __arm64_sys_pwrite64+0x170/0x200 fs/read_write.c:706
       __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.3.112/4947:
 #0: ffff0000f84f8460 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:393
 #1: ffff0000f56589c8 (&sb->s_type->i_mutex_key#26){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff0000f56589c8 (&sb->s_type->i_mutex_key#26){+.+.}-{3:3}, at: vfs_removexattr+0x6c/0x190 fs/xattr.c:535
 #2: ffff0000f56586f8 (&oi->ip_xattr_sem){++++}-{3:3}, at: ocfs2_xattr_set+0x32c/0xe98 fs/ocfs2/xattr.c:3587

stack backtrace:
CPU: 0 PID: 4947 Comm: syz.3.112 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

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/22 10:08 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_xattr_ibody_find
2025/08/22 10:08 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_xattr_ibody_find
2025/08/21 15:34 linux-6.1.y 0bc96de781b4 3e79b825 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_xattr_ibody_find
2025/08/19 23:23 linux-6.1.y 0bc96de781b4 254a27c1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_xattr_ibody_find
* Struck through repros no longer work on HEAD.