[syzbot] [ocfs2?] possible deadlock in ocfs2_get_system_file_inode

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d07b43284ab3 Merge tag 'for-linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17e20ad5980000
kernel config: https://syzkaller.appspot.com/x/.config?x=7229118d88b4a71b
dashboard link: https://syzkaller.appspot.com/bug?extid=e0055ea09f1f5e6fabdd
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13a439f3980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16d03409980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-d07b4328.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/91ceec6e19d3/vmlinux-d07b4328.xz
kernel image: https://storage.googleapis.com/syzbot-assets/be11646b0c05/bzImage-d07b4328.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/74389c5ef0e9/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e0055e...@syzkaller.appspotmail.com

JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc3-syzkaller-00060-gd07b43284ab3 #0 Not tainted
------------------------------------------------------
syz-executor524/5089 is trying to acquire lock:
ffff8880122695a8 (&osb->system_file_mutex){+.+.}-{3:3}, at: ocfs2_get_system_file_inode+0x18f/0x7b0 fs/ocfs2/sysfile.c:101

but task is already holding lock:
ffff88803a7f0660 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_expand_inline_dir fs/ocfs2/dir.c:2800 [inline]
ffff88803a7f0660 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_extend_dir+0x7f4/0x53d0 fs/ocfs2/dir.c:3181

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}:
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 fs/ocfs2/dir.c:508 [inline]
ocfs2_find_entry_el fs/ocfs2/dir.c:715 [inline]
ocfs2_find_entry+0x43b/0x2780 fs/ocfs2/dir.c:1080
ocfs2_find_files_on_disk+0xff/0x360 fs/ocfs2/dir.c:1980
ocfs2_lookup_ino_from_name+0xb1/0x1e0 fs/ocfs2/dir.c:2002
_ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:136 [inline]
ocfs2_get_system_file_inode+0x305/0x7b0 fs/ocfs2/sysfile.c:112
ocfs2_init_global_system_inodes+0x32c/0x730 fs/ocfs2/super.c:457
ocfs2_initialize_super fs/ocfs2/super.c:2250 [inline]
ocfs2_fill_super+0x3068/0x5880 fs/ocfs2/super.c:994
mount_bdev+0x20a/0x2d0 fs/super.c:1679
legacy_get_tree+0xee/0x190 fs/fs_context.c:662
vfs_get_tree+0x90/0x2a0 fs/super.c:1800
do_new_mount+0x2be/0xb40 fs/namespace.c:3472
do_mount fs/namespace.c:3812 [inline]
__do_sys_mount fs/namespace.c:4020 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3997
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 (&osb->system_file_mutex){+.+.}-{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
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
ocfs2_get_system_file_inode+0x18f/0x7b0 fs/ocfs2/sysfile.c:101
ocfs2_reserve_suballoc_bits+0x16f/0x4eb0 fs/ocfs2/suballoc.c:780
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_creat fs/open.c:1507 [inline]
__se_sys_creat fs/open.c:1501 [inline]
__x64_sys_creat+0x123/0x170 fs/open.c:1501
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:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&ocfs2_file_ip_alloc_sem_key);
lock(&osb->system_file_mutex);
lock(&ocfs2_file_ip_alloc_sem_key);
lock(&osb->system_file_mutex);

*** DEADLOCK ***

3 locks held by syz-executor524/5089:
#0: ffff88803a0de420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515
#1: ffff88803a7f09c0 (&type->i_mutex_dir_key#6){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:799 [inline]
#1: ffff88803a7f09c0 (&type->i_mutex_dir_key#6){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3644 [inline]
#1: ffff88803a7f09c0 (&type->i_mutex_dir_key#6){+.+.}-{3:3}, at: path_openat+0x7fb/0x3470 fs/namei.c:3883
#2: ffff88803a7f0660 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_expand_inline_dir fs/ocfs2/dir.c:2800 [inline]
#2: ffff88803a7f0660 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_extend_dir+0x7f4/0x53d0 fs/ocfs2/dir.c:3181

stack backtrace:
CPU: 0 UID: 0 PID: 5089 Comm: syz-executor524 Not tainted 6.11.0-rc3-syzkaller-00060-gd07b43284ab3 #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
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
ocfs2_get_system_file_inode+0x18f/0x7b0 fs/ocfs2/sysfile.c:101
ocfs2_reserve_suballoc_bits+0x16f/0x4eb0 fs/ocfs2/suballoc.c:780
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_creat fs/open.c:1507 [inline]
__se_sys_creat fs/open.c:1501 [inline]
__x64_sys_creat+0x123/0x170 fs/open.c:1501
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: 0033:0x7f4da5400a99
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc633808a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4da5400a99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0
RBP: 00007f4da54785f0 R08: 0000000000004466 R09: 0000555565ef54c0
R10: 00007ffc63380770 R11: 0000000000000246 R12: 00007ffc633808d0
R13: 00007ffc63380af8 R14: 431bde82d7b634db R15: 00007f4da544903b
</TASK>
OCFS2: ERROR (device loop0): int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *, handle_t *, u32, u32, struct ocfs2_suballoc_result *): Chain allocator dinode 23 has 4294967295 used bits but only 16777215 total
On-disk corruption discovered. Please run fsck.ocfs2 once the filesystem is unmounted.
OCFS2: Returning error to the calling process.
(syz-executor524,5089,0):ocfs2_claim_suballoc_bits:2038 ERROR: status = -5
(syz-executor524,5089,0):__ocfs2_claim_clusters:2412 ERROR: status = -5
(syz-executor524,5089,0):__ocfs2_claim_clusters:2420 ERROR: status = -5
(syz-executor524,5089,0):ocfs2_block_group_alloc_contig:437 ERROR: status = -5
(syz-executor524,5089,0):ocfs2_block_group_alloc:709 ERROR: status = -5
(syz-executor524,5089,0):ocfs2_block_group_alloc:762 ERROR: status = -5
(syz-executor524,5089,0):ocfs2_reserve_suballoc_bits:837 ERROR: status = -5
(syz-executor524,5089,0):ocfs2_reserve_suballoc_bits:854 ERROR: status = -5
(syz-executor524,5089,0):ocfs2_reserve_new_metadata_blocks:994 ERROR: status = -5
(syz-executor524,5089,0):ocfs2_reserve_new_metadata_blocks:1017 ERROR: status = -5
(syz-executor524,5089,0):ocfs2_expand_inline_dir:2821 ERROR: status = -5
(syz-executor524,5089,0):ocfs2_extend_dir:3185 ERROR: status = -5
(syz-executor524,5089,0):ocfs2_prepare_dir_for_insert:4300 ERROR: status = -5
(syz-executor524,5089,0):ocfs2_mknod:296 ERROR: status = -5
(syz-executor524,5089,0):ocfs2_mknod:500 ERROR: status = -5
(syz-executor524,5089,0):ocfs2_create:674 ERROR: status = -5
syz-executor524 (5089) used greatest stack depth: 16912 bytes left


---
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[syzbot]

syzbot has bisected this issue to:

commit a3c06ae158dd6fa8336157c31d9234689d068d02
Author: Parav Pandit <pa...@nvidia.com>
Date: Tue Jan 5 10:32:03 2021 +0000

vdpa_sim_net: Add support for user supported devices

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17ea8407980000
start commit: 196145c606d0 Merge tag 'clk-fixes-for-linus' of git://git...
git tree: upstream
final oops: https://syzkaller.appspot.com/x/report.txt?x=141a8407980000
console output: https://syzkaller.appspot.com/x/log.txt?x=101a8407980000
kernel config: https://syzkaller.appspot.com/x/.config?x=1c9e296880039df9
dashboard link: https://syzkaller.appspot.com/bug?extid=e0055ea09f1f5e6fabdd
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16fdd49f980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13f5a7c7980000

Reported-by: syzbot+e0055e...@syzkaller.appspotmail.com
Fixes: a3c06ae158dd ("vdpa_sim_net: Add support for user supported devices")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[Mohammed Anees]

#syz test

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+e0055e...@syzkaller.appspotmail.com
Tested-by: syzbot+e0055e...@syzkaller.appspotmail.com

Tested on:

commit: 2004cef1 Merge tag 'sched-core-2024-09-19' of git://gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16cd6607980000
kernel config: https://syzkaller.appspot.com/x/.config?x=38d475ce6711b8b4

dashboard link: https://syzkaller.appspot.com/bug?extid=e0055ea09f1f5e6fabdd
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=17a13b00580000

Note: testing is done by a robot and is best-effort only.

[Mohammed Anees]

#syz test

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+e0055e...@syzkaller.appspotmail.com
Tested-by: syzbot+e0055e...@syzkaller.appspotmail.com

Tested on:

commit: de5cb0dc Merge branch 'address-masking'
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17cef480580000
kernel config: https://syzkaller.appspot.com/x/.config?x=74ffdb3b3fad1a43

dashboard link: https://syzkaller.appspot.com/bug?extid=e0055ea09f1f5e6fabdd
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=12f07ca9980000

[Mohammed Anees]

#syz test

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+e0055e...@syzkaller.appspotmail.com
Tested-by: syzbot+e0055e...@syzkaller.appspotmail.com

Tested on:

commit: abf2050f Merge tag 'media/v6.12-1' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1622119f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=2a8c36c5e2b56016

dashboard link: https://syzkaller.appspot.com/bug?extid=e0055ea09f1f5e6fabdd
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=14192a27980000