[v5.15] possible deadlock in ocfs2_remap_file_range

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3a5928702e71 Linux 5.15.167
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17b74b9f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=4d3fd5cca89ae935
dashboard link: https://syzkaller.appspot.com/bug?extid=5efec5fd20aea7f08df7
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ef5025f3d708/disk-3a592870.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/776fbdad3aa8/vmlinux-3a592870.xz
kernel image: https://storage.googleapis.com/syzbot-assets/79541db5bd16/bzImage-3a592870.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5efec5...@syzkaller.appspotmail.com

ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
5.15.167-syzkaller #0 Not tainted
------------------------------------------------------
syz.0.136/4339 is trying to acquire lock:
ffff8880617e22e0 (&oi->ip_alloc_sem/1){+.+.}-{3:3}, at: ocfs2_remap_file_range+0x488/0x8d0 fs/ocfs2/file.c:2683

but task is already holding lock:
ffff88805dc84da0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_remap_file_range+0x45c/0x8d0 fs/ocfs2/file.c:2681

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
down_read+0x45/0x2e0 kernel/locking/rwsem.c:1498
ocfs2_read_virt_blocks+0x2b3/0xa10 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+0x437/0x26d0 fs/ocfs2/dir.c:1080
ocfs2_find_files_on_disk+0xea/0x310 fs/ocfs2/dir.c:1982
ocfs2_lookup_ino_from_name+0xad/0x1e0 fs/ocfs2/dir.c:2004
_ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:136 [inline]
ocfs2_get_system_file_inode+0x314/0x7b0 fs/ocfs2/sysfile.c:112
ocfs2_init_global_system_inodes+0x328/0x720 fs/ocfs2/super.c:458
ocfs2_initialize_super fs/ocfs2/super.c:2276 [inline]
ocfs2_fill_super+0x479e/0x58a0 fs/ocfs2/super.c:995
mount_bdev+0x2c9/0x3f0 fs/super.c:1398
legacy_get_tree+0xeb/0x180 fs/fs_context.c:611
vfs_get_tree+0x88/0x270 fs/super.c:1528
do_new_mount+0x2ba/0xb40 fs/namespace.c:3005
do_mount fs/namespace.c:3348 [inline]
__do_sys_mount fs/namespace.c:3556 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3533
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #1 (&osb->system_file_mutex){+.+.}-{3:3}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
ocfs2_get_system_file_inode+0x1a1/0x7b0 fs/ocfs2/sysfile.c:101
ocfs2_reserve_suballoc_bits+0x16b/0x4c70 fs/ocfs2/suballoc.c:776
ocfs2_reserve_new_metadata_blocks+0x418/0x9b0 fs/ocfs2/suballoc.c:978
ocfs2_create_refcount_tree+0x32e/0x1530 fs/ocfs2/refcounttree.c:570
ocfs2_reflink_remap_blocks+0x2f2/0x1f20 fs/ocfs2/refcounttree.c:4661
ocfs2_remap_file_range+0x5f2/0x8d0 fs/ocfs2/file.c:2691
vfs_copy_file_range+0xfc9/0x14e0 fs/read_write.c:1510
__do_sys_copy_file_range fs/read_write.c:1588 [inline]
__se_sys_copy_file_range+0x3ea/0x5d0 fs/read_write.c:1551
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&oi->ip_alloc_sem/1){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
down_write_nested+0x3b/0x60 kernel/locking/rwsem.c:1667
ocfs2_remap_file_range+0x488/0x8d0 fs/ocfs2/file.c:2683
vfs_copy_file_range+0xfc9/0x14e0 fs/read_write.c:1510
__do_sys_copy_file_range fs/read_write.c:1588 [inline]
__se_sys_copy_file_range+0x3ea/0x5d0 fs/read_write.c:1551
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

Chain exists of:
&oi->ip_alloc_sem/1 --> &osb->system_file_mutex --> &ocfs2_file_ip_alloc_sem_key

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(&oi->ip_alloc_sem/1);

*** DEADLOCK ***

4 locks held by syz.0.136/4339:
#0: ffff888028f9c460 (sb_writers#16){.+.+}-{0:0}, at: vfs_copy_file_range+0x923/0x14e0 fs/read_write.c:1494
#1: ffff88805dc85108 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
#1: ffff88805dc85108 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: lock_two_nondirectories+0xde/0x130 fs/inode.c:1118
#2: ffff8880617e2648 (&sb->s_type->i_mutex_key#23/4){+.+.}-{3:3}, at: ocfs2_reflink_inodes_lock+0x16e/0xdc0 fs/ocfs2/refcounttree.c:4729
#3: ffff88805dc84da0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_remap_file_range+0x45c/0x8d0 fs/ocfs2/file.c:2681

stack backtrace:
CPU: 0 PID: 4339 Comm: syz.0.136 Not tainted 5.15.167-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+0x1e3/0x2d0 lib/dump_stack.c:106
check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
down_write_nested+0x3b/0x60 kernel/locking/rwsem.c:1667
ocfs2_remap_file_range+0x488/0x8d0 fs/ocfs2/file.c:2683
vfs_copy_file_range+0xfc9/0x14e0 fs/read_write.c:1510
__do_sys_copy_file_range fs/read_write.c:1588 [inline]
__se_sys_copy_file_range+0x3ea/0x5d0 fs/read_write.c:1551
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9dd25f0ff9
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:00007f9dd0a69038 EFLAGS: 00000246 ORIG_RAX: 0000000000000146
RAX: ffffffffffffffda RBX: 00007f9dd27a8f80 RCX: 00007f9dd25f0ff9
RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007f9dd2663296 R08: 0000000000000006 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9dd27a8f80 R15: 00007ffdbf8d2258
</TASK>
(syz.0.136,4339,0):ocfs2_get_clusters:606 ERROR: status = -34
(syz.0.136,4339,0):ocfs2_reflink_remap_extent:4540 ERROR: status = -34
(syz.0.136,4339,0):ocfs2_reflink_remap_blocks:4699 ERROR: status = -34
(syz.0.136,4339,0):ocfs2_remap_file_range:2698 ERROR: status = -34
syz.0.136 (4339) used greatest stack depth: 19224 bytes left


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 3a5928702e71 Linux 5.15.167
git tree: linux-5.15.y

console output: https://syzkaller.appspot.com/x/log.txt?x=179c1307980000

kernel config: https://syzkaller.appspot.com/x/.config?x=4d3fd5cca89ae935
dashboard link: https://syzkaller.appspot.com/bug?extid=5efec5fd20aea7f08df7
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=13baab9f980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=145c1307980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ef5025f3d708/disk-3a592870.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/776fbdad3aa8/vmlinux-3a592870.xz
kernel image: https://storage.googleapis.com/syzbot-assets/79541db5bd16/bzImage-3a592870.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/c8477cdd3807/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5efec5...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 32768
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
5.15.167-syzkaller #0 Not tainted
------------------------------------------------------

syz-executor162/3676 is trying to acquire lock:
ffff88806d4a6a20 (&oi->ip_alloc_sem/1){+.+.}-{3:3}, at: ocfs2_remap_file_range+0x488/0x8d0 fs/ocfs2/file.c:2683

but task is already holding lock:

ffff88806f69dbe0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_remap_file_range+0x45c/0x8d0 fs/ocfs2/file.c:2681

4 locks held by syz-executor162/3676:
#0: ffff88801fe96460 (sb_writers#9){.+.+}-{0:0}, at: vfs_copy_file_range+0x923/0x14e0 fs/read_write.c:1494
#1: ffff88806d4a6d88 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
#1: ffff88806d4a6d88 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: lock_two_nondirectories+0xde/0x130 fs/inode.c:1118
#2: ffff88806f69df48 (&sb->s_type->i_mutex_key#15/4){+.+.}-{3:3}, at: ocfs2_reflink_inodes_lock+0x16e/0xdc0 fs/ocfs2/refcounttree.c:4729
#3: ffff88806f69dbe0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_remap_file_range+0x45c/0x8d0 fs/ocfs2/file.c:2681

stack backtrace:
CPU: 0 PID: 3676 Comm: syz-executor162 Not tainted 5.15.167-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+0x1e3/0x2d0 lib/dump_stack.c:106
check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
down_write_nested+0x3b/0x60 kernel/locking/rwsem.c:1667
ocfs2_remap_file_range+0x488/0x8d0 fs/ocfs2/file.c:2683
vfs_copy_file_range+0xfc9/0x14e0 fs/read_write.c:1510
__do_sys_copy_file_range fs/read_write.c:1588 [inline]
__se_sys_copy_file_range+0x3ea/0x5d0 fs/read_write.c:1551
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0

RIP: 0033:0x7f2f76e9a1e9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 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:00007fff105eab18 EFLAGS: 00000246 ORIG_RAX: 0000000000000146
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f2f76e9a1e9

RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000006

RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00007fff105eab4c
R13: 0000000000000025 R14: 431bde82d7b634db R15: 00007fff105eab80
</TASK>
(syz-executor162,3676,0):ocfs2_get_clusters:606 ERROR: status = -34
(syz-executor162,3676,0):ocfs2_reflink_remap_extent:4540 ERROR: status = -34
(syz-executor162,3676,0):ocfs2_reflink_remap_blocks:4699 ERROR: status = -34
(syz-executor162,3676,0):ocfs2_remap_file_range:2698 ERROR: status = -34


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

[syzbot]

syzbot suspects this issue could be fixed by backporting the following commit:

commit 7bf1823e010e8db2fb649c790bd1b449a75f52d8
git tree: upstream
Author: Mohammed Anees <pvmohamme...@gmail.com>
Date: Tue Sep 24 09:32:57 2024 +0000

ocfs2: fix deadlock in ocfs2_get_system_file_inode

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11c0aa3f980000

kernel config: https://syzkaller.appspot.com/x/.config?x=4d3fd5cca89ae935
dashboard link: https://syzkaller.appspot.com/bug?extid=5efec5fd20aea7f08df7

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13baab9f980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=145c1307980000

Please keep in mind that other backports might be required as well.

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