syzbot


possible deadlock in ocfs2_write_begin_nolock

Status: upstream: reported on 2024/10/11 23:44
Reported-by: syzbot+13376da5d4f789911f90@syzkaller.appspotmail.com
First crash: 18d, last: 8h38m
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in ocfs2_write_begin_nolock ocfs2 C 41 2d07h 48d 0/28 upstream: reported C repro on 2024/09/12 09:35
linux-5.15 possible deadlock in ocfs2_write_begin_nolock 1 3d18h 3d18h 0/3 upstream: reported on 2024/10/27 04:30

Sample crash report:
ocfs2: Mounting device (7,4) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.1.114-syzkaller #0 Not tainted
------------------------------------------------------
syz.4.4065/24203 is trying to acquire lock:
ffff8880656da650 (sb_internal#3){.+.+}-{0:0}, at: ocfs2_write_begin_inline fs/ocfs2/aops.c:1481 [inline]
ffff8880656da650 (sb_internal#3){.+.+}-{0:0}, at: ocfs2_try_to_write_inline_data fs/ocfs2/aops.c:1584 [inline]
ffff8880656da650 (sb_internal#3){.+.+}-{0:0}, at: ocfs2_write_begin_nolock+0x2073/0x4e40 fs/ocfs2/aops.c:1670

but task is already holding lock:
ffff888040293120 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_write_begin+0x1cd/0x390 fs/ocfs2/aops.c:1902

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}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       ocfs2_try_remove_refcount_tree+0xb2/0x330 fs/ocfs2/refcounttree.c:932
       ocfs2_xattr_set+0xa4b/0x1930 fs/ocfs2/xattr.c:3674
       ocfs2_set_acl+0x4cb/0x570 fs/ocfs2/acl.c:254
       ocfs2_iop_set_acl+0x252/0x3c0 fs/ocfs2/acl.c:285
       set_posix_acl fs/posix_acl.c:1160 [inline]
       posix_acl_xattr_set+0x37b/0x3e0 fs/posix_acl.c:1189
       __vfs_removexattr+0x3ce/0x410 fs/xattr.c:479
       __vfs_removexattr_locked+0x1fe/0x410 fs/xattr.c:514
       vfs_removexattr+0xff/0x2a0 fs/xattr.c:536
       removexattr fs/xattr.c:878 [inline]
       path_removexattr+0x22a/0x320 fs/xattr.c:892
       __do_sys_lremovexattr fs/xattr.c:912 [inline]
       __se_sys_lremovexattr fs/xattr.c:909 [inline]
       __x64_sys_lremovexattr+0x59/0x70 fs/xattr.c:909
       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

-> #3 (&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_create+0x1c0/0x4e0 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3482 [inline]
       open_last_lookups fs/namei.c:3550 [inline]
       path_openat+0x12f1/0x2e60 fs/namei.c:3780
       do_filp_open+0x230/0x480 fs/namei.c:3810
       do_sys_openat2+0x13b/0x4f0 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]
       __x64_sys_openat+0x243/0x290 fs/open.c:1345
       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

-> #2 (jbd2_handle){++++}-{0:0}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       start_this_handle+0x1f71/0x21b0 fs/jbd2/transaction.c:463
       jbd2__journal_start+0x2d1/0x5c0 fs/jbd2/transaction.c:520
       jbd2_journal_start+0x25/0x30 fs/jbd2/transaction.c:559
       ocfs2_start_trans+0x3c0/0x6f0 fs/ocfs2/journal.c:354
       ocfs2_mknod+0x1638/0x2e20 fs/ocfs2/namei.c:359
       ocfs2_create+0x1c0/0x4e0 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3482 [inline]
       open_last_lookups fs/namei.c:3550 [inline]
       path_openat+0x12f1/0x2e60 fs/namei.c:3780
       do_filp_open+0x230/0x480 fs/namei.c:3810
       do_sys_openat2+0x13b/0x4f0 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]
       __x64_sys_openat+0x243/0x290 fs/open.c:1345
       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 (&journal->j_trans_barrier){.+.+}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_read+0xad/0xa30 kernel/locking/rwsem.c:1520
       ocfs2_start_trans+0x3b5/0x6f0 fs/ocfs2/journal.c:352
       ocfs2_mknod+0x1638/0x2e20 fs/ocfs2/namei.c:359
       ocfs2_create+0x1c0/0x4e0 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3482 [inline]
       open_last_lookups fs/namei.c:3550 [inline]
       path_openat+0x12f1/0x2e60 fs/namei.c:3780
       do_filp_open+0x230/0x480 fs/namei.c:3810
       do_sys_openat2+0x13b/0x4f0 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]
       __x64_sys_openat+0x243/0x290 fs/open.c:1345
       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

-> #0 (sb_internal#3){.+.+}-{0:0}:
       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
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1891 [inline]
       sb_start_intwrite include/linux/fs.h:2013 [inline]
       ocfs2_start_trans+0x2b0/0x6f0 fs/ocfs2/journal.c:350
       ocfs2_write_begin_inline fs/ocfs2/aops.c:1481 [inline]
       ocfs2_try_to_write_inline_data fs/ocfs2/aops.c:1584 [inline]
       ocfs2_write_begin_nolock+0x2073/0x4e40 fs/ocfs2/aops.c:1670
       ocfs2_write_begin+0x201/0x390 fs/ocfs2/aops.c:1904
       generic_perform_write+0x2fc/0x5e0 mm/filemap.c:3845
       __generic_file_write_iter+0x176/0x400 mm/filemap.c:3973
       ocfs2_file_write_iter+0x17c6/0x2020 fs/ocfs2/file.c:2456
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x857/0xbc0 fs/read_write.c:584
       ksys_write+0x19c/0x2c0 fs/read_write.c:637
       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:
  sb_internal#3 --> &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);
  lock(sb_internal#3);

 *** DEADLOCK ***

4 locks held by syz.4.4065/24203:
 #0: ffff888073e57268 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ba/0x360 fs/file.c:1031
 #1: ffff8880656da460 (sb_writers#34){.+.+}-{0:0}, at: vfs_write+0x269/0xbc0 fs/read_write.c:580
 #2: ffff888040293488 (&sb->s_type->i_mutex_key#38){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #2: ffff888040293488 (&sb->s_type->i_mutex_key#38){+.+.}-{3:3}, at: ocfs2_file_write_iter+0x476/0x2020 fs/ocfs2/file.c:2388
 #3: ffff888040293120 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_write_begin+0x1cd/0x390 fs/ocfs2/aops.c:1902

stack backtrace:
CPU: 0 PID: 24203 Comm: syz.4.4065 Not tainted 6.1.114-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1891 [inline]
 sb_start_intwrite include/linux/fs.h:2013 [inline]
 ocfs2_start_trans+0x2b0/0x6f0 fs/ocfs2/journal.c:350
 ocfs2_write_begin_inline fs/ocfs2/aops.c:1481 [inline]
 ocfs2_try_to_write_inline_data fs/ocfs2/aops.c:1584 [inline]
 ocfs2_write_begin_nolock+0x2073/0x4e40 fs/ocfs2/aops.c:1670
 ocfs2_write_begin+0x201/0x390 fs/ocfs2/aops.c:1904
 generic_perform_write+0x2fc/0x5e0 mm/filemap.c:3845
 __generic_file_write_iter+0x176/0x400 mm/filemap.c:3973
 ocfs2_file_write_iter+0x17c6/0x2020 fs/ocfs2/file.c:2456
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x857/0xbc0 fs/read_write.c:584
 ksys_write+0x19c/0x2c0 fs/read_write.c:637
 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: 0033:0x7f749737dff9
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:00007f7498181038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7497535f80 RCX: 00007f749737dff9
RDX: 0000000000000118 RSI: 0000000020000180 RDI: 0000000000000004
RBP: 00007f74973f0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f7497535f80 R15: 00007fff17bc4a68
 </TASK>

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/23 18:33 linux-6.1.y 7ec6f9fa3d97 15fa2979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in ocfs2_write_begin_nolock
2024/10/23 18:33 linux-6.1.y 7ec6f9fa3d97 15fa2979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in ocfs2_write_begin_nolock
2024/10/30 14:44 linux-6.1.y 7ec6f9fa3d97 fb888278 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_write_begin_nolock
2024/10/23 13:08 linux-6.1.y 7ec6f9fa3d97 15fa2979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_write_begin_nolock
2024/10/23 13:07 linux-6.1.y 7ec6f9fa3d97 15fa2979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_write_begin_nolock
2024/10/22 15:38 linux-6.1.y 7ec6f9fa3d97 a93682b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_write_begin_nolock
2024/10/22 15:38 linux-6.1.y 7ec6f9fa3d97 a93682b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_write_begin_nolock
2024/10/11 23:44 linux-6.1.y aa4cd140bba5 084d8178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in ocfs2_write_begin_nolock
* Struck through repros no longer work on HEAD.