syzbot


possible deadlock in ocfs2_read_virt_blocks

Status: upstream: reported on 2024/09/12 09:36
Subsystems: ocfs2
[Documentation on labels]
Reported-by: syzbot+8b11b4c34ed0362b217a@syzkaller.appspotmail.com
First crash: 28d, last: 28d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ocfs2?] possible deadlock in ocfs2_read_virt_blocks 0 (1) 2024/09/12 09:36

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc7-syzkaller-00021-g7c6a3a65ace7 #0 Not tainted
------------------------------------------------------
syz.0.0/5120 is trying to acquire lock:
ffff88804b8c3f60 (&oi->ip_alloc_sem){++++}-{3:3}, at: ocfs2_read_virt_blocks+0x2ca/0xa50 fs/ocfs2/extent_map.c:976

but task is already holding lock:
ffff88803d352958 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1e94/0x2110 fs/jbd2/transaction.c:448

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (jbd2_handle){++++}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       start_this_handle+0x1eb4/0x2110 fs/jbd2/transaction.c:448
       jbd2__journal_start+0x2da/0x5d0 fs/jbd2/transaction.c:505
       jbd2_journal_start+0x29/0x40 fs/jbd2/transaction.c:544
       ocfs2_start_trans+0x3c9/0x700 fs/ocfs2/journal.c:352
       ocfs2_mknod+0x150c/0x2b40 fs/ocfs2/namei.c:359
       ocfs2_mkdir+0x1ab/0x480 fs/ocfs2/namei.c:655
       vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4210
       do_mkdirat+0x264/0x3a0 fs/namei.c:4233
       __do_sys_mkdirat fs/namei.c:4248 [inline]
       __se_sys_mkdirat fs/namei.c:4246 [inline]
       __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4246
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #4 (&journal->j_trans_barrier){.+.+}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526
       ocfs2_start_trans+0x3be/0x700 fs/ocfs2/journal.c:350
       ocfs2_mknod+0x150c/0x2b40 fs/ocfs2/namei.c:359
       ocfs2_mkdir+0x1ab/0x480 fs/ocfs2/namei.c:655
       vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4210
       do_mkdirat+0x264/0x3a0 fs/namei.c:4233
       __do_sys_mkdirat fs/namei.c:4248 [inline]
       __se_sys_mkdirat fs/namei.c:4246 [inline]
       __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4246
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #3 (sb_internal#2){.+.+}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1676 [inline]
       sb_start_intwrite include/linux/fs.h:1859 [inline]
       ocfs2_start_trans+0x2b9/0x700 fs/ocfs2/journal.c:348
       ocfs2_mknod+0x150c/0x2b40 fs/ocfs2/namei.c:359
       ocfs2_mkdir+0x1ab/0x480 fs/ocfs2/namei.c:655
       vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4210
       do_mkdirat+0x264/0x3a0 fs/namei.c:4233
       __do_sys_mkdirat fs/namei.c:4248 [inline]
       __se_sys_mkdirat fs/namei.c:4246 [inline]
       __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4246
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       down_write+0x99/0x220 kernel/locking/rwsem.c:1579
       inode_lock include/linux/fs.h:800 [inline]
       ocfs2_reserve_local_alloc_bits+0x132/0x2870 fs/ocfs2/localalloc.c:636
       ocfs2_reserve_clusters_with_limit+0x1b8/0xb60 fs/ocfs2/suballoc.c:1166
       ocfs2_mknod+0x1486/0x2b40 fs/ocfs2/namei.c:352
       ocfs2_mkdir+0x1ab/0x480 fs/ocfs2/namei.c:655
       vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4210
       do_mkdirat+0x264/0x3a0 fs/namei.c:4233
       __do_sys_mkdirat fs/namei.c:4248 [inline]
       __se_sys_mkdirat fs/namei.c:4246 [inline]
       __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4246
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#3){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       down_write+0x99/0x220 kernel/locking/rwsem.c:1579
       inode_lock include/linux/fs.h:800 [inline]
       ocfs2_reserve_suballoc_bits+0x192/0x4eb0 fs/ocfs2/suballoc.c:786
       ocfs2_reserve_new_metadata_blocks+0x41c/0x9c0 fs/ocfs2/suballoc.c:982
       ocfs2_expand_inline_dir fs/ocfs2/dir.c:2819 [inline]
       ocfs2_extend_dir+0xdef/0x53d0 fs/ocfs2/dir.c:3181
       ocfs2_prepare_dir_for_insert+0x33d1/0x5c70 fs/ocfs2/dir.c:4296
       ocfs2_mknod+0xcaf/0x2b40 fs/ocfs2/namei.c:292
       ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3578 [inline]
       open_last_lookups fs/namei.c:3647 [inline]
       path_openat+0x1a9a/0x3470 fs/namei.c:3883
       do_filp_open+0x235/0x490 fs/namei.c:3913
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1416
       do_sys_open fs/open.c:1431 [inline]
       __do_sys_openat fs/open.c:1447 [inline]
       __se_sys_openat fs/open.c:1442 [inline]
       __x64_sys_openat+0x247/0x2a0 fs/open.c:1442
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&oi->ip_alloc_sem){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3133 [inline]
       check_prevs_add kernel/locking/lockdep.c:3252 [inline]
       validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
       __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526
       ocfs2_read_virt_blocks+0x2ca/0xa50 fs/ocfs2/extent_map.c:976
       ocfs2_read_dir_block+0x106/0x5c0 fs/ocfs2/dir.c:508
       ocfs2_dir_foreach_blk_el fs/ocfs2/dir.c:1827 [inline]
       ocfs2_dir_foreach_blk+0x2ca/0x1b20 fs/ocfs2/dir.c:1913
       ocfs2_dir_foreach fs/ocfs2/dir.c:1923 [inline]
       ocfs2_empty_dir+0x134/0x800 fs/ocfs2/dir.c:2137
       ocfs2_rename+0x25f1/0x4210 fs/ocfs2/namei.c:1498
       vfs_rename+0xbdb/0xf00 fs/namei.c:4966
       do_renameat2+0xd94/0x13f0 fs/namei.c:5123
       __do_sys_rename fs/namei.c:5170 [inline]
       __se_sys_rename fs/namei.c:5168 [inline]
       __x64_sys_rename+0x82/0x90 fs/namei.c:5168
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &oi->ip_alloc_sem --> &journal->j_trans_barrier --> jbd2_handle

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(jbd2_handle);
                               lock(&journal->j_trans_barrier);
                               lock(jbd2_handle);
  rlock(&oi->ip_alloc_sem);

 *** DEADLOCK ***

7 locks held by syz.0.0/5120:
 #0: ffff8880120d2420 (sb_writers#10){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515
 #1: ffff88804b8f89c0 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:835 [inline]
 #1: ffff88804b8f89c0 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: lock_rename fs/namei.c:3147 [inline]
 #1: ffff88804b8f89c0 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: do_renameat2+0x62c/0x13f0 fs/namei.c:5058
 #2: ffff88804b8c42c0 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:800 [inline]
 #2: ffff88804b8c42c0 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: vfs_rename+0x6cb/0xf00 fs/namei.c:4931
 #3: ffff88804b8fdf40 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:800 [inline]
 #3: ffff88804b8fdf40 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]){+.+.}-{3:3}, at: ocfs2_lookup_lock_orphan_dir+0x102/0x350 fs/ocfs2/namei.c:2127
 #4: ffff8880120d2610 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_rename+0x1ebe/0x4210 fs/ocfs2/namei.c:1487
 #5: ffff88801259bce8 (&journal->j_trans_barrier){.+.+}-{3:3}, at: ocfs2_start_trans+0x3be/0x700 fs/ocfs2/journal.c:350
 #6: ffff88803d352958 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1e94/0x2110 fs/jbd2/transaction.c:448

stack backtrace:
CPU: 0 UID: 0 PID: 5120 Comm: syz.0.0 Not tainted 6.11.0-rc7-syzkaller-00021-g7c6a3a65ace7 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186
 check_prev_add kernel/locking/lockdep.c:3133 [inline]
 check_prevs_add kernel/locking/lockdep.c:3252 [inline]
 validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526
 ocfs2_read_virt_blocks+0x2ca/0xa50 fs/ocfs2/extent_map.c:976
 ocfs2_read_dir_block+0x106/0x5c0 fs/ocfs2/dir.c:508
 ocfs2_dir_foreach_blk_el fs/ocfs2/dir.c:1827 [inline]
 ocfs2_dir_foreach_blk+0x2ca/0x1b20 fs/ocfs2/dir.c:1913
 ocfs2_dir_foreach fs/ocfs2/dir.c:1923 [inline]
 ocfs2_empty_dir+0x134/0x800 fs/ocfs2/dir.c:2137
 ocfs2_rename+0x25f1/0x4210 fs/ocfs2/namei.c:1498
 vfs_rename+0xbdb/0xf00 fs/namei.c:4966
 do_renameat2+0xd94/0x13f0 fs/namei.c:5123
 __do_sys_rename fs/namei.c:5170 [inline]
 __se_sys_rename fs/namei.c:5168 [inline]
 __x64_sys_rename+0x82/0x90 fs/namei.c:5168
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0ffc77def9
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:00007f0ffd512038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f0ffc936058 RCX: 00007f0ffc77def9
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000020000200
RBP: 00007f0ffc7f0b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f0ffc936058 R15: 00007ffcf5c18e98
 </TASK>
(syz.0.0,5120,0):ocfs2_rename:1698 ERROR: status = -39

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/12 05:38 upstream 7c6a3a65ace7 d94c83d8 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in ocfs2_read_virt_blocks
* Struck through repros no longer work on HEAD.