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possible deadlock in ocfs2_truncate_file

Status: upstream: reported on 2025/10/29 01:22
Reported-by: syzbot+3d51b2cc4d20cb5cde9f@syzkaller.appspotmail.com
First crash: 81d, last: 81d
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 possible deadlock in ocfs2_truncate_file origin:lts-only 4 C error 35 13d 473d 0/3 upstream: reported C repro on 2024/10/02 11:36
upstream possible deadlock in ocfs2_truncate_file ocfs2 4 C 695 1d20h 512d 0/29 upstream: reported C repro on 2024/08/24 04:12
linux-6.1 possible deadlock in ocfs2_truncate_file origin:lts-only 4 C inconclusive 26 6d22h 413d 0/3 upstream: reported C repro on 2024/12/01 05:06

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.1033/10113 is trying to acquire lock:
ffff88807883a608 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_orphan_for_truncate fs/ocfs2/file.c:396 [inline]
ffff88807883a608 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_truncate_file+0x611/0x13a0 fs/ocfs2/file.c:500

but task is already holding lock:
ffff88805de294a0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_truncate_file+0x32a/0x13a0 fs/ocfs2/file.c:471

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&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_xattr_set+0x596/0x11f0 fs/ocfs2/xattr.c:3669
       ocfs2_set_acl+0x4e1/0x590 fs/ocfs2/acl.c:254
       ocfs2_iop_set_acl+0x1ab/0x2a0 fs/ocfs2/acl.c:286
       set_posix_acl fs/posix_acl.c:956 [inline]
       vfs_set_acl+0x803/0xa60 fs/posix_acl.c:1135
       do_setxattr fs/xattr.c:627 [inline]
       path_setxattr+0x39f/0x550 fs/xattr.c:659
       __do_sys_setxattr fs/xattr.c:677 [inline]
       __se_sys_setxattr fs/xattr.c:673 [inline]
       __x64_sys_setxattr+0xbb/0xd0 fs/xattr.c:673
       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

-> #3 (&oi->ip_xattr_sem){++++}-{3:3}:
       down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520
       ocfs2_init_acl+0x2fa/0x720 fs/ocfs2/acl.c:366
       ocfs2_mknod+0x12e5/0x20f0 fs/ocfs2/namei.c:410
       ocfs2_create+0x196/0x410 fs/ocfs2/namei.c:674
       lookup_open fs/namei.c:3496 [inline]
       open_last_lookups fs/namei.c:3564 [inline]
       path_openat+0x1277/0x3190 fs/namei.c:3794
       do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
       do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
       do_sys_open fs/open.c:1434 [inline]
       __do_sys_open fs/open.c:1442 [inline]
       __se_sys_open fs/open.c:1438 [inline]
       __x64_sys_open+0x11f/0x140 fs/open.c:1438
       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 (jbd2_handle){++++}-{0:0}:
       start_this_handle+0x1e9d/0x20c0 fs/jbd2/transaction.c:448
       jbd2__journal_start+0x2bb/0x5b0 fs/jbd2/transaction.c:505
       jbd2_journal_start+0x2a/0x40 fs/jbd2/transaction.c:544
       ocfs2_start_trans+0x376/0x6c0 fs/ocfs2/journal.c:374
       ocfs2_mknod+0xe47/0x20f0 fs/ocfs2/namei.c:361
       ocfs2_create+0x196/0x410 fs/ocfs2/namei.c:674
       lookup_open fs/namei.c:3496 [inline]
       open_last_lookups fs/namei.c:3564 [inline]
       path_openat+0x1277/0x3190 fs/namei.c:3794
       do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
       do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
       do_sys_open fs/open.c:1434 [inline]
       __do_sys_open fs/open.c:1442 [inline]
       __se_sys_open fs/open.c:1438 [inline]
       __x64_sys_open+0x11f/0x140 fs/open.c:1438
       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 (&journal->j_trans_barrier){.+.+}-{3:3}:
       down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520
       ocfs2_start_trans+0x36a/0x6c0 fs/ocfs2/journal.c:372
       ocfs2_mknod+0xe47/0x20f0 fs/ocfs2/namei.c:361
       ocfs2_create+0x196/0x410 fs/ocfs2/namei.c:674
       lookup_open fs/namei.c:3496 [inline]
       open_last_lookups fs/namei.c:3564 [inline]
       path_openat+0x1277/0x3190 fs/namei.c:3794
       do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
       do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
       do_sys_open fs/open.c:1434 [inline]
       __do_sys_open fs/open.c:1442 [inline]
       __se_sys_open fs/open.c:1438 [inline]
       __x64_sys_open+0x11f/0x140 fs/open.c:1438
       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 (sb_internal#2){.+.+}-{0:0}:
       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
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1633 [inline]
       sb_start_intwrite include/linux/fs.h:1755 [inline]
       ocfs2_start_trans+0x26b/0x6c0 fs/ocfs2/journal.c:370
       ocfs2_orphan_for_truncate fs/ocfs2/file.c:396 [inline]
       ocfs2_truncate_file+0x611/0x13a0 fs/ocfs2/file.c:500
       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:3299 [inline]
       do_open fs/namei.c:3644 [inline]
       path_openat+0x298c/0x3190 fs/namei.c:3797
       do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
       do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
       do_sys_open fs/open.c:1434 [inline]
       __do_sys_openat fs/open.c:1450 [inline]
       __se_sys_openat fs/open.c:1445 [inline]
       __x64_sys_openat+0x139/0x160 fs/open.c:1445
       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:
  sb_internal#2 --> &oi->ip_xattr_sem --> &ocfs2_file_ip_alloc_sem_key

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_file_ip_alloc_sem_key);
                               lock(&oi->ip_xattr_sem);
                               lock(&ocfs2_file_ip_alloc_sem_key);
  rlock(sb_internal#2);

 *** DEADLOCK ***

3 locks held by syz.1.1033/10113:
 #0: ffff88807883a418 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
 #1: ffff88805de29818 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #1: ffff88805de29818 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: do_truncate+0x187/0x220 fs/open.c:64
 #2: ffff88805de294a0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_truncate_file+0x32a/0x13a0 fs/ocfs2/file.c:471

stack backtrace:
CPU: 0 PID: 10113 Comm: syz.1.1033 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1633 [inline]
 sb_start_intwrite include/linux/fs.h:1755 [inline]
 ocfs2_start_trans+0x26b/0x6c0 fs/ocfs2/journal.c:370
 ocfs2_orphan_for_truncate fs/ocfs2/file.c:396 [inline]
 ocfs2_truncate_file+0x611/0x13a0 fs/ocfs2/file.c:500
 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:3299 [inline]
 do_open fs/namei.c:3644 [inline]
 path_openat+0x298c/0x3190 fs/namei.c:3797
 do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
 do_sys_open fs/open.c:1434 [inline]
 __do_sys_openat fs/open.c:1450 [inline]
 __se_sys_openat fs/open.c:1445 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1445
 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: 0033:0x7fb87218efc9
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:00007fb8703b4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fb8723e6180 RCX: 00007fb87218efc9
RDX: 0000000000044642 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007fb872211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb8723e6218 R14: 00007fb8723e6180 R15: 00007ffd5b40e998
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/29 01:21 linux-6.6.y 4a243110dc88 fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in ocfs2_truncate_file
* Struck through repros no longer work on HEAD.