Message-ID: <000000000000cd1e8b06181d6198@google.com>
Date: Fri, 10 May 2024 11:05:34 -0700
From: syzbot <syzbot+1ac5b398842451b74cec@...kaller.appspotmail.com>
To: chandan.babu@...cle.com, djwong@...nel.org, linux-kernel@...r.kernel.org, 
	linux-xfs@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [xfs?] possible deadlock in xfs_can_free_eofblocks

Hello,

syzbot found the following issue on:

HEAD commit:    dd5a440a31fa Linux 6.9-rc7
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11059824980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6d14c12b661fb43
dashboard link: https://syzkaller.appspot.com/bug?extid=1ac5b398842451b74cec
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/58e2a4900479/disk-dd5a440a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/246a109c32d6/vmlinux-dd5a440a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d2719f7eb672/bzImage-dd5a440a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1ac5b398842451b74cec@...kaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.9.0-rc7-syzkaller #0 Not tainted
------------------------------------------------------
kswapd0/89 is trying to acquire lock:
ffff8880540b9858
 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_can_free_eofblocks+0x645/0x910 fs/xfs/xfs_bmap_util.c:555

but task is already holding lock:
ffffffff8e42a780 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6782 [inline]
ffffffff8e42a780 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbe8/0x38a0 mm/vmscan.c:7164

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (fs_reclaim){+.+.}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __fs_reclaim_acquire mm/page_alloc.c:3698 [inline]
       fs_reclaim_acquire+0x88/0x140 mm/page_alloc.c:3712
       might_alloc include/linux/sched/mm.h:312 [inline]
       slab_pre_alloc_hook mm/slub.c:3746 [inline]
       slab_alloc_node mm/slub.c:3827 [inline]
       kmalloc_trace+0x47/0x360 mm/slub.c:3992
       kmalloc include/linux/slab.h:628 [inline]
       add_stack_record_to_list mm/page_owner.c:177 [inline]
       inc_stack_record_count mm/page_owner.c:219 [inline]
       __set_page_owner+0x561/0x810 mm/page_owner.c:334
       set_page_owner include/linux/page_owner.h:32 [inline]
       post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1534
       prep_new_page mm/page_alloc.c:1541 [inline]
       get_page_from_freelist+0x3410/0x35b0 mm/page_alloc.c:3317
       __alloc_pages+0x256/0x6c0 mm/page_alloc.c:4575
       alloc_pages_mpol+0x3e8/0x680 mm/mempolicy.c:2264
       stack_depot_save_flags+0x666/0x830 lib/stackdepot.c:635
       kasan_save_stack mm/kasan/common.c:48 [inline]
       kasan_save_track+0x51/0x80 mm/kasan/common.c:68
       poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
       __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
       kasan_kmalloc include/linux/kasan.h:211 [inline]
       kmalloc_trace+0x1db/0x360 mm/slub.c:3997
       kmalloc include/linux/slab.h:628 [inline]
       kzalloc include/linux/slab.h:749 [inline]
       xfs_iext_alloc_node fs/xfs/libxfs/xfs_iext_tree.c:401 [inline]
       xfs_iext_alloc_root fs/xfs/libxfs/xfs_iext_tree.c:593 [inline]
       xfs_iext_insert_raw+0x206/0x23d0 fs/xfs/libxfs/xfs_iext_tree.c:645
       xfs_iext_insert+0x38/0x250 fs/xfs/libxfs/xfs_iext_tree.c:684
       xfs_bmap_add_extent_hole_delay+0x573/0xc20 fs/xfs/libxfs/xfs_bmap.c:2686
       xfs_bmapi_reserve_delalloc+0x897/0x9b0 fs/xfs/libxfs/xfs_bmap.c:4128
       xfs_buffered_write_iomap_begin+0x1243/0x1b40 fs/xfs/xfs_iomap.c:1130
       iomap_iter+0x693/0xf60 fs/iomap/iter.c:91
       iomap_zero_range+0x16e/0x6e0 fs/iomap/buffered-io.c:1426
       xfs_setattr_size+0x384/0xc80 fs/xfs/xfs_iops.c:858
       xfs_vn_setattr+0x25d/0x320 fs/xfs/xfs_iops.c:1020
       notify_change+0xb9f/0xe70 fs/attr.c:497
       do_truncate fs/open.c:65 [inline]
       do_ftruncate+0x46b/0x590 fs/open.c:181
       do_sys_ftruncate fs/open.c:199 [inline]
       __do_sys_ftruncate fs/open.c:207 [inline]
       __se_sys_ftruncate fs/open.c:205 [inline]
       __x64_sys_ftruncate+0x95/0xf0 fs/open.c:205
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&xfs_nondir_ilock_class#3){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1651
       xfs_can_free_eofblocks+0x645/0x910 fs/xfs/xfs_bmap_util.c:555
       xfs_inode_mark_reclaimable+0x1bb/0xf60 fs/xfs/xfs_icache.c:2149
       destroy_inode fs/inode.c:311 [inline]
       evict+0x54b/0x630 fs/inode.c:682
       dispose_list fs/inode.c:700 [inline]
       prune_icache_sb+0x239/0x2f0 fs/inode.c:885
       super_cache_scan+0x38c/0x4b0 fs/super.c:223
       do_shrink_slab+0x707/0x1160 mm/shrinker.c:435
       shrink_slab_memcg mm/shrinker.c:548 [inline]
       shrink_slab+0x883/0x14d0 mm/shrinker.c:626
       shrink_one+0x453/0x880 mm/vmscan.c:4774
       shrink_many mm/vmscan.c:4835 [inline]
       lru_gen_shrink_node mm/vmscan.c:4935 [inline]
       shrink_node+0x3b17/0x4310 mm/vmscan.c:5894
       kswapd_shrink_node mm/vmscan.c:6704 [inline]
       balance_pgdat mm/vmscan.c:6895 [inline]
       kswapd+0x1882/0x38a0 mm/vmscan.c:7164
       kthread+0x2f2/0x390 kernel/kthread.c:388
       ret_from_fork+0x4d/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:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(fs_reclaim);
                               lock(&xfs_nondir_ilock_class#3);
                               lock(fs_reclaim);
  rlock(&xfs_nondir_ilock_class#3);

 *** DEADLOCK ***

2 locks held by kswapd0/89:
 #0: ffffffff8e42a780 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6782 [inline]
 #0: ffffffff8e42a780 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbe8/0x38a0 mm/vmscan.c:7164
 #1: ffff8880796d20e0 (&type->s_umount_key#66){++++}-{3:3}, at: super_trylock_shared fs/super.c:561 [inline]
 #1: ffff8880796d20e0 (&type->s_umount_key#66){++++}-{3:3}, at: super_cache_scan+0x94/0x4b0 fs/super.c:196

stack backtrace:
CPU: 0 PID: 89 Comm: kswapd0 Not tainted 6.9.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_noncircular+0x36a/0x4a0 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+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
 down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1651
 xfs_can_free_eofblocks+0x645/0x910 fs/xfs/xfs_bmap_util.c:555
 xfs_inode_mark_reclaimable+0x1bb/0xf60 fs/xfs/xfs_icache.c:2149
 destroy_inode fs/inode.c:311 [inline]
 evict+0x54b/0x630 fs/inode.c:682
 dispose_list fs/inode.c:700 [inline]
 prune_icache_sb+0x239/0x2f0 fs/inode.c:885
 super_cache_scan+0x38c/0x4b0 fs/super.c:223
 do_shrink_slab+0x707/0x1160 mm/shrinker.c:435
 shrink_slab_memcg mm/shrinker.c:548 [inline]
 shrink_slab+0x883/0x14d0 mm/shrinker.c:626
 shrink_one+0x453/0x880 mm/vmscan.c:4774
 shrink_many mm/vmscan.c:4835 [inline]
 lru_gen_shrink_node mm/vmscan.c:4935 [inline]
 shrink_node+0x3b17/0x4310 mm/vmscan.c:5894
 kswapd_shrink_node mm/vmscan.c:6704 [inline]
 balance_pgdat mm/vmscan.c:6895 [inline]
 kswapd+0x1882/0x38a0 mm/vmscan.c:7164
 kthread+0x2f2/0x390 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@...glegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

Powered by blists - more mailing lists