syzbot


possible deadlock in __ocfs2_write_remove_suid

Status: upstream: reported on 2024/11/02 15:20
Subsystems: ocfs2
[Documentation on labels]
Reported-by: syzbot+61eb9f5be190a23ea4df@syzkaller.appspotmail.com
First crash: 150d, last: 3d22h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ocfs2?] possible deadlock in __ocfs2_write_remove_suid 0 (1) 2024/11/02 15:20

Sample crash report:
loop0: detected capacity change from 0 to 262144
JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
capability: warning: `syz.0.0' uses deprecated v2 capabilities in a way that may be insecure
======================================================
WARNING: possible circular locking dependency detected
6.13.0-rc7-syzkaller-00043-g619f0b6fad52 #0 Not tainted
------------------------------------------------------
syz.0.0/5314 is trying to acquire lock:
ffff8880430c0610 (sb_internal#2){.+.+}-{0:0}, at: __ocfs2_write_remove_suid+0x1bf/0x7e0 fs/ocfs2/file.c:1385

but task is already holding lock:
ffff8880441a3120 (&oi->ip_alloc_sem){++++}-{4:4}, at: ocfs2_inode_lock_for_extent_tree+0xcf/0x180 fs/ocfs2/file.c:2210

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&oi->ip_alloc_sem){++++}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       ocfs2_xattr_ibody_set+0x12c/0xd00 fs/ocfs2/xattr.c:2783
       __ocfs2_xattr_set_handle+0x128/0x10a0 fs/ocfs2/xattr.c:3322
       ocfs2_xattr_set+0x128c/0x1930 fs/ocfs2/xattr.c:3650
       __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
       do_setxattr fs/xattr.c:636 [inline]
       filename_setxattr+0x2af/0x430 fs/xattr.c:665
       path_setxattrat+0x440/0x510 fs/xattr.c:713
       __do_sys_lsetxattr fs/xattr.c:754 [inline]
       __se_sys_lsetxattr fs/xattr.c:750 [inline]
       __x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:750
       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:5849
       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_modify_bh+0xed/0x4d0 fs/ocfs2/quota_local.c:101
       ocfs2_local_read_info+0x158f/0x19f0 fs/ocfs2/quota_local.c:771
       dquot_load_quota_sb+0x762/0xbb0 fs/quota/dquot.c:2459
       dquot_load_quota_inode+0x320/0x600 fs/quota/dquot.c:2496
       ocfs2_enable_quotas+0x169/0x450 fs/ocfs2/super.c:926
       ocfs2_fill_super+0x4ca1/0x5760 fs/ocfs2/super.c:1141
       mount_bdev+0x20a/0x2d0 fs/super.c:1693
       legacy_get_tree+0xee/0x190 fs/fs_context.c:662
       vfs_get_tree+0x90/0x2b0 fs/super.c:1814
       do_new_mount+0x2be/0xb40 fs/namespace.c:3511
       do_mount fs/namespace.c:3851 [inline]
       __do_sys_mount fs/namespace.c:4061 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4038
       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){.+.+}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524
       ocfs2_start_trans+0x3be/0x700 fs/ocfs2/journal.c:350
       ocfs2_modify_bh+0xed/0x4d0 fs/ocfs2/quota_local.c:101
       ocfs2_local_read_info+0x158f/0x19f0 fs/ocfs2/quota_local.c:771
       dquot_load_quota_sb+0x762/0xbb0 fs/quota/dquot.c:2459
       dquot_load_quota_inode+0x320/0x600 fs/quota/dquot.c:2496
       ocfs2_enable_quotas+0x169/0x450 fs/ocfs2/super.c:926
       ocfs2_fill_super+0x4ca1/0x5760 fs/ocfs2/super.c:1141
       mount_bdev+0x20a/0x2d0 fs/super.c:1693
       legacy_get_tree+0xee/0x190 fs/fs_context.c:662
       vfs_get_tree+0x90/0x2b0 fs/super.c:1814
       do_new_mount+0x2be/0xb40 fs/namespace.c:3511
       do_mount fs/namespace.c:3851 [inline]
       __do_sys_mount fs/namespace.c:4061 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4038
       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+0x1397/0x2100 kernel/locking/lockdep.c:5226
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1725 [inline]
       sb_start_intwrite include/linux/fs.h:1908 [inline]
       ocfs2_start_trans+0x2b9/0x700 fs/ocfs2/journal.c:348
       __ocfs2_write_remove_suid+0x1bf/0x7e0 fs/ocfs2/file.c:1385
       ocfs2_write_remove_suid fs/ocfs2/file.c:1426 [inline]
       ocfs2_prepare_inode_for_write fs/ocfs2/file.c:2311 [inline]
       ocfs2_file_write_iter+0xb3a/0x2180 fs/ocfs2/file.c:2451
       new_sync_write fs/read_write.c:586 [inline]
       vfs_write+0xaeb/0xd30 fs/read_write.c:679
       ksys_write+0x18f/0x2b0 fs/read_write.c:731
       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 --> jbd2_handle --> &oi->ip_alloc_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(&oi->ip_alloc_sem);
                               lock(jbd2_handle);
                               lock(&oi->ip_alloc_sem);
  rlock(sb_internal#2);

 *** DEADLOCK ***

4 locks held by syz.0.0/5314:
 #0: ffff888037bd0478 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x254/0x320 fs/file.c:1192
 #1: ffff8880430c0420 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2964 [inline]
 #1: ffff8880430c0420 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:675
 #2: ffff8880441a3480 (&sb->s_type->i_mutex_key#21){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
 #2: ffff8880441a3480 (&sb->s_type->i_mutex_key#21){+.+.}-{4:4}, at: ocfs2_file_write_iter+0x445/0x2180 fs/ocfs2/file.c:2399
 #3: ffff8880441a3120 (&oi->ip_alloc_sem){++++}-{4:4}, at: ocfs2_inode_lock_for_extent_tree+0xcf/0x180 fs/ocfs2/file.c:2210

stack backtrace:
CPU: 0 UID: 0 PID: 5314 Comm: syz.0.0 Not tainted 6.13.0-rc7-syzkaller-00043-g619f0b6fad52 #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: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+0x1397/0x2100 kernel/locking/lockdep.c:5226
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1725 [inline]
 sb_start_intwrite include/linux/fs.h:1908 [inline]
 ocfs2_start_trans+0x2b9/0x700 fs/ocfs2/journal.c:348
 __ocfs2_write_remove_suid+0x1bf/0x7e0 fs/ocfs2/file.c:1385
 ocfs2_write_remove_suid fs/ocfs2/file.c:1426 [inline]
 ocfs2_prepare_inode_for_write fs/ocfs2/file.c:2311 [inline]
 ocfs2_file_write_iter+0xb3a/0x2180 fs/ocfs2/file.c:2451
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0xaeb/0xd30 fs/read_write.c:679
 ksys_write+0x18f/0x2b0 fs/read_write.c:731
 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: 0033:0x7f5b8b985d29
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:00007f5b8c735038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5b8bb75fa0 RCX: 00007f5b8b985d29
RDX: 0000000000000069 RSI: 0000000020000040 RDI: 0000000000000008
RBP: 00007f5b8ba01b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5b8bb75fa0 R15: 00007ffc1c0463b8
 </TASK>
syz.0.0 (5314) used greatest stack depth: 17144 bytes left

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/16 13:26 upstream 619f0b6fad52 968edaf4 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in __ocfs2_write_remove_suid
2025/01/04 22:01 upstream ab75170520d4 f3558dbf .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in __ocfs2_write_remove_suid
2025/03/25 04:23 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci a2392f333575 875573af .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in __ocfs2_write_remove_suid
2024/10/29 15:11 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 1bf329c696cf 66aeb999 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in __ocfs2_write_remove_suid
* Struck through repros no longer work on HEAD.