[syzbot] [jfs?] possible deadlock in jfs_create

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 50736169ecc8 Merge tag 'for-6.10-rc4-tag' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14c0d08e980000
kernel config: https://syzkaller.appspot.com/x/.config?x=d24262d81a9225c6
dashboard link: https://syzkaller.appspot.com/bug?extid=bdacb5fa2bf85deafea9
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-50736169.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c6c00759502a/vmlinux-50736169.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c94681a1aaa3/bzImage-50736169.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bdacb5...@syzkaller.appspotmail.com

loop2: detected capacity change from 0 to 32768
======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc4-syzkaller-00148-g50736169ecc8 #0 Not tainted
------------------------------------------------------
syz-executor.2/9183 is trying to acquire lock:
ffff88804c874288 (&jfs_ip->commit_mutex/1){+.+.}-{3:3}, at: jfs_create+0x2c3/0xb40 fs/jfs/namei.c:101

but task is already holding lock:
ffff88804c873948 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_create+0x2a7/0xb40 fs/jfs/namei.c:100

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (&jfs_ip->commit_mutex){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
diNewIAG fs/jfs/jfs_imap.c:2519 [inline]
diAllocExt fs/jfs/jfs_imap.c:1902 [inline]
diAllocAG+0xc59/0x2300 fs/jfs/jfs_imap.c:1666
diAlloc+0x8f7/0x1a70 fs/jfs/jfs_imap.c:1587
ialloc+0x84/0x9e0 fs/jfs/jfs_inode.c:56
jfs_mkdir+0x244/0xb30 fs/jfs/namei.c:225
vfs_mkdir+0x57d/0x860 fs/namei.c:4131
do_mkdirat+0x301/0x3a0 fs/namei.c:4154
__do_sys_mkdir fs/namei.c:4174 [inline]
__se_sys_mkdir fs/namei.c:4172 [inline]
__ia32_sys_mkdir+0xf0/0x140 fs/namei.c:4172
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #4 (&jfs_ip->rdwrlock/1){++++}-{3:3}:
__lock_release kernel/locking/lockdep.c:5468 [inline]
lock_release+0x33e/0x6c0 kernel/locking/lockdep.c:5774
__mutex_unlock_slowpath+0xa3/0x650 kernel/locking/mutex.c:912
diNewIAG fs/jfs/jfs_imap.c:2634 [inline]
diAllocExt fs/jfs/jfs_imap.c:1902 [inline]
diAllocAG+0x912/0x2300 fs/jfs/jfs_imap.c:1666
diAlloc+0x8f7/0x1a70 fs/jfs/jfs_imap.c:1587
ialloc+0x84/0x9e0 fs/jfs/jfs_inode.c:56
jfs_mkdir+0x244/0xb30 fs/jfs/namei.c:225
vfs_mkdir+0x57d/0x860 fs/namei.c:4131
do_mkdirat+0x301/0x3a0 fs/namei.c:4154
__do_sys_mkdir fs/namei.c:4174 [inline]
__se_sys_mkdir fs/namei.c:4172 [inline]
__ia32_sys_mkdir+0xf0/0x140 fs/namei.c:4172
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #3 (&(imap->im_aglock[index])){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
diFree+0x2ff/0x2770 fs/jfs/jfs_imap.c:886
jfs_evict_inode+0x3d4/0x4b0 fs/jfs/inode.c:156
evict+0x2ed/0x6c0 fs/inode.c:667
iput_final fs/inode.c:1741 [inline]
iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
iput+0x5c/0x80 fs/inode.c:1757
dentry_unlink_inode+0x295/0x480 fs/dcache.c:400
__dentry_kill+0x1d0/0x600 fs/dcache.c:603
shrink_kill fs/dcache.c:1048 [inline]
shrink_dentry_list+0x140/0x5d0 fs/dcache.c:1075
prune_dcache_sb+0xeb/0x150 fs/dcache.c:1156
super_cache_scan+0x32a/0x550 fs/super.c:221
do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435
shrink_slab_memcg mm/shrinker.c:548 [inline]
shrink_slab+0xa87/0x1310 mm/shrinker.c:626
shrink_one+0x493/0x7c0 mm/vmscan.c:4790
shrink_many mm/vmscan.c:4851 [inline]
lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
shrink_node mm/vmscan.c:5910 [inline]
kswapd_shrink_node mm/vmscan.c:6720 [inline]
balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #2 (fs_reclaim){+.+.}-{0:0}:
__fs_reclaim_acquire mm/page_alloc.c:3801 [inline]
fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815
might_alloc include/linux/sched/mm.h:334 [inline]
slab_pre_alloc_hook mm/slub.c:3891 [inline]
slab_alloc_node mm/slub.c:3981 [inline]
__do_kmalloc_node mm/slub.c:4121 [inline]
__kmalloc_noprof+0xb5/0x420 mm/slub.c:4135
kmalloc_noprof include/linux/slab.h:664 [inline]
ea_get+0x21f/0x12c0 fs/jfs/xattr.c:487
__jfs_setxattr+0x1ed/0xfb0 fs/jfs/xattr.c:720
__jfs_xattr_set+0xc6/0x150 fs/jfs/xattr.c:919
__vfs_setxattr+0x173/0x1e0 fs/xattr.c:200
__vfs_setxattr_noperm+0x127/0x660 fs/xattr.c:234
__vfs_setxattr_locked+0x182/0x260 fs/xattr.c:295
vfs_setxattr+0x146/0x350 fs/xattr.c:321
do_setxattr+0x146/0x170 fs/xattr.c:629
setxattr+0x15d/0x180 fs/xattr.c:652
path_setxattr+0x179/0x1e0 fs/xattr.c:671
__do_sys_lsetxattr fs/xattr.c:694 [inline]
__se_sys_lsetxattr fs/xattr.c:690 [inline]
__ia32_sys_lsetxattr+0xbd/0x160 fs/xattr.c:690
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #1 (&jfs_ip->xattr_sem){++++}-{3:3}:
down_read+0x9a/0x330 kernel/locking/rwsem.c:1526
__jfs_getxattr+0xee/0x360 fs/jfs/xattr.c:807
jfs_get_acl+0x7c/0x170 fs/jfs/acl.c:38
__get_acl+0x378/0x4e0 fs/posix_acl.c:159
get_inode_acl fs/posix_acl.c:184 [inline]
posix_acl_create+0x14c/0x5f0 fs/posix_acl.c:647
jfs_init_acl+0x9a/0x3a0 fs/jfs/acl.c:135
jfs_mkdir+0x2df/0xb30 fs/jfs/namei.c:236
vfs_mkdir+0x57d/0x860 fs/namei.c:4131
do_mkdirat+0x301/0x3a0 fs/namei.c:4154
__do_sys_mkdir fs/namei.c:4174 [inline]
__se_sys_mkdir fs/namei.c:4172 [inline]
__ia32_sys_mkdir+0xf0/0x140 fs/namei.c:4172
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #0 (&jfs_ip->commit_mutex/1){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
jfs_create+0x2c3/0xb40 fs/jfs/namei.c:101
lookup_open.isra.0+0x10a1/0x13c0 fs/namei.c:3505
open_last_lookups fs/namei.c:3574 [inline]
path_openat+0x92f/0x29f0 fs/namei.c:3804
do_filp_open+0x1dc/0x430 fs/namei.c:3834
do_sys_openat2+0x17a/0x1e0 fs/open.c:1405
do_sys_open fs/open.c:1420 [inline]
__do_compat_sys_openat fs/open.c:1480 [inline]
__se_compat_sys_openat fs/open.c:1478 [inline]
__ia32_compat_sys_openat+0x16e/0x210 fs/open.c:1478
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e

other info that might help us debug this:

Chain exists of:
&jfs_ip->commit_mutex/1 --> &jfs_ip->rdwrlock/1 --> &jfs_ip->commit_mutex

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&jfs_ip->commit_mutex);
lock(&jfs_ip->rdwrlock/1);
lock(&jfs_ip->commit_mutex);
lock(&jfs_ip->commit_mutex/1);

*** DEADLOCK ***

3 locks held by syz-executor.2/9183:
#0: ffff888057d1c420 (sb_writers#29){.+.+}-{0:0}, at: open_last_lookups fs/namei.c:3563 [inline]
#0: ffff888057d1c420 (sb_writers#29){.+.+}-{0:0}, at: path_openat+0x19e6/0x29f0 fs/namei.c:3804
#1: ffff88804c873d00 (&type->i_mutex_dir_key#13){++++}-{3:3}, at: inode_lock include/linux/fs.h:791 [inline]
#1: ffff88804c873d00 (&type->i_mutex_dir_key#13){++++}-{3:3}, at: open_last_lookups fs/namei.c:3571 [inline]
#1: ffff88804c873d00 (&type->i_mutex_dir_key#13){++++}-{3:3}, at: path_openat+0x8c7/0x29f0 fs/namei.c:3804
#2: ffff88804c873948 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_create+0x2a7/0xb40 fs/jfs/namei.c:100

stack backtrace:
CPU: 3 PID: 9183 Comm: syz-executor.2 Not tainted 6.10.0-rc4-syzkaller-00148-g50736169ecc8 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
jfs_create+0x2c3/0xb40 fs/jfs/namei.c:101
lookup_open.isra.0+0x10a1/0x13c0 fs/namei.c:3505
open_last_lookups fs/namei.c:3574 [inline]
path_openat+0x92f/0x29f0 fs/namei.c:3804
do_filp_open+0x1dc/0x430 fs/namei.c:3834
do_sys_openat2+0x17a/0x1e0 fs/open.c:1405
do_sys_open fs/open.c:1420 [inline]
__do_compat_sys_openat fs/open.c:1480 [inline]
__se_compat_sys_openat fs/open.c:1478 [inline]
__ia32_compat_sys_openat+0x16e/0x210 fs/open.c:1478
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf72ca579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f5ebc5ac EFLAGS: 00000292 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 0000000020000040
RDX: 000000000000275a RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
0: 10 06 adc %al,(%rsi)
2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi
6: 10 07 adc %al,(%rdi)
8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi
c: 10 08 adc %cl,(%rax)
e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi
1e: 00 51 52 add %dl,0x52(%rcx)
21: 55 push %rbp
22: 89 e5 mov %esp,%ebp
24: 0f 34 sysenter
26: cd 80 int $0x80
* 28: 5d pop %rbp <-- trapping instruction
29: 5a pop %rdx
2a: 59 pop %rcx
2b: c3 ret
2c: 90 nop
2d: 90 nop
2e: 90 nop
2f: 90 nop
30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi


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