[syzbot] [jfs?] possible deadlock in diFree

From: syzbot
Date: Mon Apr 22 2024 - 11:24:45 EST


Hello,

syzbot found the following issue on:

HEAD commit: 8cd26fd90c1a Merge tag 'for-6.9-rc4-tag' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17246653180000
kernel config: https://syzkaller.appspot.com/x/.config?x=2dc5adfa93a8cfac
dashboard link: https://syzkaller.appspot.com/bug?extid=ff2b5414e8547b96ad2e
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-8cd26fd9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7f65e88496b8/vmlinux-8cd26fd9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/cc0f0ec3d904/bzImage-8cd26fd9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ff2b5414e8547b96ad2e@xxxxxxxxxxxxxxxxxxxxxxxxx

======================================================
WARNING: possible circular locking dependency detected
6.9.0-rc4-syzkaller-00038-g8cd26fd90c1a #0 Not tainted
------------------------------------------------------
kswapd0/111 is trying to acquire lock:
ffff88801e3e8920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diFree+0x2ff/0x2770 fs/jfs/jfs_imap.c:886

but task is already holding lock:
ffffffff8d9373c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x166/0x1a10 mm/vmscan.c:6782

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (fs_reclaim){+.+.}-{0:0}:
__fs_reclaim_acquire mm/page_alloc.c:3698 [inline]
fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3712
might_alloc include/linux/sched/mm.h:312 [inline]
prepare_alloc_pages.constprop.0+0x155/0x560 mm/page_alloc.c:4346
__alloc_pages+0x194/0x2460 mm/page_alloc.c:4564
__alloc_pages_node include/linux/gfp.h:238 [inline]
alloc_pages_node include/linux/gfp.h:261 [inline]
__kmalloc_large_node+0x7f/0x1a0 mm/slub.c:3911
kmalloc_large+0x1c/0x70 mm/slub.c:3928
kmalloc include/linux/slab.h:625 [inline]
diMount+0x29/0x8d0 fs/jfs/jfs_imap.c:105
jfs_mount_rw+0x238/0x700 fs/jfs/jfs_mount.c:240
jfs_remount+0x51f/0x650 fs/jfs/super.c:454
legacy_reconfigure+0x119/0x180 fs/fs_context.c:685
reconfigure_super+0x44f/0xb20 fs/super.c:1071
vfs_cmd_reconfigure fs/fsopen.c:267 [inline]
vfs_fsconfig_locked fs/fsopen.c:296 [inline]
__do_sys_fsconfig+0x991/0xb90 fs/fsopen.c:476
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:321
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:346
entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #1 (&jfs_ip->rdwrlock/1){++++}-{3:3}:
down_read_nested+0x9e/0x330 kernel/locking/rwsem.c:1651
diAlloc+0x3ea/0x1a70 fs/jfs/jfs_imap.c:1385
ialloc+0x84/0x9e0 fs/jfs/jfs_inode.c:56
jfs_create+0x23e/0xb40 fs/jfs/namei.c:92
lookup_open.isra.0+0x10a1/0x13c0 fs/namei.c:3497
open_last_lookups fs/namei.c:3566 [inline]
path_openat+0x92f/0x2990 fs/namei.c:3796
do_filp_open+0x1dc/0x430 fs/namei.c:3826
do_sys_openat2+0x17a/0x1e0 fs/open.c:1406
do_sys_open fs/open.c:1421 [inline]
__do_compat_sys_openat fs/open.c:1481 [inline]
__se_compat_sys_openat fs/open.c:1479 [inline]
__ia32_compat_sys_openat+0x16e/0x210 fs/open.c:1479
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:321
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:346
entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #0 (&(imap->im_aglock[index])){+.+.}-{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
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+0x295/0x440 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:4774
shrink_many mm/vmscan.c:4835 [inline]
lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4935
shrink_node mm/vmscan.c:5894 [inline]
kswapd_shrink_node mm/vmscan.c:6704 [inline]
balance_pgdat+0x10d1/0x1a10 mm/vmscan.c:6895
kswapd+0x5ea/0xbf0 mm/vmscan.c:7164
kthread+0x2c1/0x3a0 kernel/kthread.c:388
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

other info that might help us debug this:

Chain exists of:
&(imap->im_aglock[index]) --> &jfs_ip->rdwrlock/1 --> fs_reclaim

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(&jfs_ip->rdwrlock/1);
lock(fs_reclaim);
lock(&(imap->im_aglock[index]));

*** DEADLOCK ***

2 locks held by kswapd0/111:
#0: ffffffff8d9373c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x166/0x1a10 mm/vmscan.c:6782
#1: ffff88804a6d80e0 (&type->s_umount_key#65){++++}-{3:3}, at: super_trylock_shared fs/super.c:561 [inline]
#1: ffff88804a6d80e0 (&type->s_umount_key#65){++++}-{3:3}, at: super_cache_scan+0x96/0x550 fs/super.c:196

stack backtrace:
CPU: 3 PID: 111 Comm: kswapd0 Not tainted 6.9.0-rc4-syzkaller-00038-g8cd26fd90c1a #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
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+0x295/0x440 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:4774
shrink_many mm/vmscan.c:4835 [inline]
lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4935
shrink_node mm/vmscan.c:5894 [inline]
kswapd_shrink_node mm/vmscan.c:6704 [inline]
balance_pgdat+0x10d1/0x1a10 mm/vmscan.c:6895
kswapd+0x5ea/0xbf0 mm/vmscan.c:7164
kthread+0x2c1/0x3a0 kernel/kthread.c:388
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>


---
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