syzbot


possible deadlock in ocfs2_remove_btree_range

Status: upstream: reported on 2024/10/28 00:59
Subsystems: ocfs2
[Documentation on labels]
Reported-by: syzbot+f459794c08272fdcd5b6@syzkaller.appspotmail.com
First crash: 44d, last: 13d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ocfs2?] possible deadlock in ocfs2_remove_btree_range 0 (1) 2024/10/28 00:59
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 possible deadlock in ocfs2_remove_btree_range 1 83d 83d 0/3 upstream: reported on 2024/09/15 02:14

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc4-syzkaller-00047-gc2ee9f594da8 #0 Not tainted
------------------------------------------------------
syz.4.35/5492 is trying to acquire lock:
ffff888025bb0610 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_remove_btree_range+0x8e4/0x1860 fs/ocfs2/alloc.c:5752

but task is already holding lock:
ffff88805ecb5100 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
ffff88805ecb5100 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: ocfs2_remove_btree_range+0x737/0x1860 fs/ocfs2/alloc.c:5742

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       inode_lock include/linux/fs.h:815 [inline]
       ocfs2_xattr_set+0xe9e/0x1930 fs/ocfs2/xattr.c:3623
       __vfs_setxattr+0x468/0x4a0 fs/xattr.c:200
       __vfs_setxattr_noperm+0x12e/0x660 fs/xattr.c:234
       vfs_setxattr+0x221/0x430 fs/xattr.c:321
       ovl_do_setxattr fs/overlayfs/overlayfs.h:314 [inline]
       ovl_setxattr fs/overlayfs/overlayfs.h:326 [inline]
       ovl_make_workdir fs/overlayfs/super.c:696 [inline]
       ovl_get_workdir+0xd90/0x1920 fs/overlayfs/super.c:808
       ovl_fill_super+0x12a8/0x3560 fs/overlayfs/super.c:1376
       vfs_get_super fs/super.c:1280 [inline]
       get_tree_nodev+0xb7/0x140 fs/super.c:1299
       vfs_get_tree+0x90/0x2b0 fs/super.c:1800
       do_new_mount+0x2be/0xb40 fs/namespace.c:3507
       do_mount fs/namespace.c:3847 [inline]
       __do_sys_mount fs/namespace.c:4057 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034
       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 (&oi->ip_xattr_sem){++++}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524
       ocfs2_init_acl+0x397/0x930 fs/ocfs2/acl.c:366
       ocfs2_mknod+0x1c05/0x2b40 fs/ocfs2/namei.c:408
       ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3595 [inline]
       open_last_lookups fs/namei.c:3694 [inline]
       path_openat+0x1c03/0x3590 fs/namei.c:3930
       do_filp_open+0x235/0x490 fs/namei.c:3960
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
       do_sys_open fs/open.c:1430 [inline]
       __do_sys_creat fs/open.c:1508 [inline]
       __se_sys_creat fs/open.c:1502 [inline]
       __x64_sys_creat+0x123/0x170 fs/open.c:1502
       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 (jbd2_handle){++++}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       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_block_group_alloc fs/ocfs2/suballoc.c:685 [inline]
       ocfs2_reserve_suballoc_bits+0x9f6/0x4eb0 fs/ocfs2/suballoc.c:832
       ocfs2_reserve_new_metadata_blocks+0x41c/0x9c0 fs/ocfs2/suballoc.c:982
       ocfs2_mknod+0x143a/0x2b40 fs/ocfs2/namei.c:345
       ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3595 [inline]
       open_last_lookups fs/namei.c:3694 [inline]
       path_openat+0x1c03/0x3590 fs/namei.c:3930
       do_filp_open+0x235/0x490 fs/namei.c:3960
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
       do_sys_open fs/open.c:1430 [inline]
       __do_sys_creat fs/open.c:1508 [inline]
       __se_sys_creat fs/open.c:1502 [inline]
       __x64_sys_creat+0x123/0x170 fs/open.c:1502
       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 (&journal->j_trans_barrier){.+.+}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524
       ocfs2_start_trans+0x3be/0x700 fs/ocfs2/journal.c:350
       ocfs2_block_group_alloc fs/ocfs2/suballoc.c:685 [inline]
       ocfs2_reserve_suballoc_bits+0x9f6/0x4eb0 fs/ocfs2/suballoc.c:832
       ocfs2_reserve_new_metadata_blocks+0x41c/0x9c0 fs/ocfs2/suballoc.c:982
       ocfs2_mknod+0x143a/0x2b40 fs/ocfs2/namei.c:345
       ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3595 [inline]
       open_last_lookups fs/namei.c:3694 [inline]
       path_openat+0x1c03/0x3590 fs/namei.c:3930
       do_filp_open+0x235/0x490 fs/namei.c:3960
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
       do_sys_open fs/open.c:1430 [inline]
       __do_sys_creat fs/open.c:1508 [inline]
       __se_sys_creat fs/open.c:1502 [inline]
       __x64_sys_creat+0x123/0x170 fs/open.c:1502
       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 (sb_internal#2){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
       __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1716 [inline]
       sb_start_intwrite include/linux/fs.h:1899 [inline]
       ocfs2_start_trans+0x2b9/0x700 fs/ocfs2/journal.c:348
       ocfs2_remove_btree_range+0x8e4/0x1860 fs/ocfs2/alloc.c:5752
       ocfs2_remove_inode_range+0x166d/0x2690 fs/ocfs2/file.c:1899
       __ocfs2_change_file_space+0x8e4/0xfd0 fs/ocfs2/file.c:2020
       ocfs2_fallocate+0x2e4/0x350 fs/ocfs2/file.c:2130
       vfs_fallocate+0x569/0x6e0 fs/open.c:333
       do_vfs_ioctl+0x2583/0x2e40 fs/ioctl.c:886
       __do_sys_ioctl fs/ioctl.c:905 [inline]
       __se_sys_ioctl+0x81/0x170 fs/ioctl.c:893
       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:
  sb_internal#2 --> &oi->ip_xattr_sem --> &ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6);
                               lock(&oi->ip_xattr_sem);
                               lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6);
  rlock(sb_internal#2);

 *** DEADLOCK ***

4 locks held by syz.4.35/5492:
 #0: ffff888025bb0420 (sb_writers#16){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ffff888025bb0420 (sb_writers#16){.+.+}-{0:0}, at: vfs_fallocate+0x4fe/0x6e0 fs/open.c:332
 #1: ffff88805ecb6d80 (&sb->s_type->i_mutex_key#23){++++}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
 #1: ffff88805ecb6d80 (&sb->s_type->i_mutex_key#23){++++}-{3:3}, at: __ocfs2_change_file_space+0x201/0xfd0 fs/ocfs2/file.c:1941
 #2: ffff88805ecb6a20 (&oi->ip_alloc_sem){++++}-{3:3}, at: __ocfs2_change_file_space+0x7ff/0xfd0 fs/ocfs2/file.c:2007
 #3: ffff88805ecb5100 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
 #3: ffff88805ecb5100 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: ocfs2_remove_btree_range+0x737/0x1860 fs/ocfs2/alloc.c:5742

stack backtrace:
CPU: 1 UID: 0 PID: 5492 Comm: syz.4.35 Not tainted 6.12.0-rc4-syzkaller-00047-gc2ee9f594da8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1716 [inline]
 sb_start_intwrite include/linux/fs.h:1899 [inline]
 ocfs2_start_trans+0x2b9/0x700 fs/ocfs2/journal.c:348
 ocfs2_remove_btree_range+0x8e4/0x1860 fs/ocfs2/alloc.c:5752
 ocfs2_remove_inode_range+0x166d/0x2690 fs/ocfs2/file.c:1899
 __ocfs2_change_file_space+0x8e4/0xfd0 fs/ocfs2/file.c:2020
 ocfs2_fallocate+0x2e4/0x350 fs/ocfs2/file.c:2130
 vfs_fallocate+0x569/0x6e0 fs/open.c:333
 do_vfs_ioctl+0x2583/0x2e40 fs/ioctl.c:886
 __do_sys_ioctl fs/ioctl.c:905 [inline]
 __se_sys_ioctl+0x81/0x170 fs/ioctl.c:893
 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: 0033:0x7fe59c97dff9
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:00007fe59d7a1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe59cb36058 RCX: 00007fe59c97dff9
RDX: 00000000200000c0 RSI: 0000000040305829 RDI: 0000000000000005
RBP: 00007fe59c9f0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe59cb36058 R15: 00007ffeff1e25a8
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/24 00:50 upstream c2ee9f594da8 15fa2979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_remove_btree_range
2024/11/23 19:56 linux-next cfba9f07a1d6 68da6d95 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in ocfs2_remove_btree_range
* Struck through repros no longer work on HEAD.