Re: [syzbot] [ocfs2?] general protection fault in ocfs2_buffer_cached

syzbot
2024-09-06T20:28:02Z

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING: bad unlock balance in ocfs2_read_blocks

loop0: detected capacity change from 0 to 32768
(syz.0.15,5612,0):ocfs2_read_blocks:240 ERROR: status = -12
=====================================
WARNING: bad unlock balance detected!
6.11.0-rc6-syzkaller-g788220eee30d-dirty #0 Not tainted
-------------------------------------
syz.0.15/5612 is trying to release lock (&oi->ip_io_mutex) at:
[<ffffffff837f5e56>] ocfs2_read_blocks+0x11c6/0x1620 fs/ocfs2/buffer_head_io.c:394
but there are no more locks to release!

other info that might help us debug this:
2 locks held by syz.0.15/5612:
#0: ffff8880166e00e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x221/0x9d0 fs/super.c:344
#1: ffff8880434fd5a8 (&osb->system_file_mutex){+.+.}-{3:3}, at: ocfs2_get_system_file_inode+0x18f/0x7b0 fs/ocfs2/sysfile.c:101

stack backtrace:
CPU: 0 UID: 0 PID: 5612 Comm: syz.0.15 Not tainted 6.11.0-rc6-syzkaller-g788220eee30d-dirty #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
print_unlock_imbalance_bug+0x256/0x2c0 kernel/locking/lockdep.c:5199
__lock_release kernel/locking/lockdep.c:5436 [inline]
lock_release+0x5cb/0xa30 kernel/locking/lockdep.c:5780
__mutex_unlock_slowpath+0xe2/0x750 kernel/locking/mutex.c:912
ocfs2_read_blocks+0x11c6/0x1620 fs/ocfs2/buffer_head_io.c:394
ocfs2_read_virt_blocks+0x4c8/0xa50 fs/ocfs2/extent_map.c:1010
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+0x90/0x2b0 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
RIP: 0033:0x7f66b2b7b0ba
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 7e 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f66b38efe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f66b38efef0 RCX: 00007f66b2b7b0ba
RDX: 0000000020004480 RSI: 00000000200044c0 RDI: 00007f66b38efeb0
RBP: 0000000020004480 R08: 00007f66b38efef0 R09: 0000000002800400
R10: 0000000002800400 R11: 0000000000000246 R12: 00000000200044c0
R13: 00007f66b38efeb0 R14: 0000000000004475 R15: 00000000200001c0
</TASK>
(syz.0.15,5612,0):ocfs2_read_virt_blocks:1013 ERROR: status = -12
(syz.0.15,5612,0):ocfs2_read_dir_block:511 ERROR: status = -12
(syz.0.15,5612,0):ocfs2_init_global_system_inodes:461 ERROR: status = -22
(syz.0.15,5612,0):ocfs2_init_global_system_inodes:463 ERROR: Unable to load system inode 1, possibly corrupt fs?
(syz.0.15,5612,0):ocfs2_init_global_system_inodes:472 ERROR: status = -22
(syz.0.15,5612,0):ocfs2_initialize_super:2252 ERROR: status = -22
(syz.0.15,5612,0):ocfs2_fill_super:1178 ERROR: status = -22

Tested on:

commit: 788220ee Merge tag 'pm-6.11-rc7' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16802200580000
kernel config: https://syzkaller.appspot.com/x/.config?x=14f90d959c4a3f08
dashboard link: https://syzkaller.appspot.com/bug?extid=adfd64e93c46b99c957e
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=115a6567980000