Hello, syzbot found the following issue on: HEAD commit: 55cb5f43689d Merge tag 'trace-v6.7-rc6' of git://git.kerne.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1167b176e80000 kernel config: https://syzkaller.appspot.com/x/.config?x=314e9ad033a7d3a7 dashboard link: https://syzkaller.appspot.com/bug?extid=903350d47ddb4cbb7f6f 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-55cb5f43.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/ba0e1e5966ee/vmlinux-55cb5f43.xz kernel image: https://storage.googleapis.com/syzbot-assets/4212fc08c5ac/bzImage-55cb5f43.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+903350d47ddb4cbb7f6f@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.7.0-rc6-syzkaller-00022-g55cb5f43689d #0 Not tainted ------------------------------------------------------ kswapd0/108 is trying to acquire lock: ffff888079954608 (sb_internal#4){.+.+}-{0:0}, at: nilfs_dirty_inode+0x1a0/0x270 fs/nilfs2/inode.c:1158 but task is already holding lock: ffffffff8d11c740 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x160/0x1a90 mm/vmscan.c:6746 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:3693 [inline] fs_reclaim_acquire+0x100/0x150 mm/page_alloc.c:3707 might_alloc include/linux/sched/mm.h:303 [inline] prepare_alloc_pages.constprop.0+0x155/0x550 mm/page_alloc.c:4339 __alloc_pages+0x193/0x2420 mm/page_alloc.c:4557 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133 folio_alloc+0x1e/0xe0 mm/mempolicy.c:2211 filemap_alloc_folio+0x3bb/0x490 mm/filemap.c:974 __filemap_get_folio+0x54c/0xaa0 mm/filemap.c:1918 pagecache_get_page+0x2c/0x250 mm/folio-compat.c:99 block_write_begin+0x38/0x490 fs/buffer.c:2223 nilfs_write_begin+0x9f/0x1a0 fs/nilfs2/inode.c:261 page_symlink+0x391/0x490 fs/namei.c:5187 nilfs_symlink+0x24f/0x3e0 fs/nilfs2/namei.c:153 vfs_symlink fs/namei.c:4464 [inline] vfs_symlink+0x3e4/0x620 fs/namei.c:4448 do_symlinkat+0x25f/0x310 fs/namei.c:4490 __do_sys_symlinkat fs/namei.c:4506 [inline] __se_sys_symlinkat fs/namei.c:4503 [inline] __ia32_sys_symlinkat+0x97/0xc0 fs/namei.c:4503 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x62/0xe0 arch/x86/entry/common.c:321 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x70/0x7a -> #1 (&nilfs->ns_segctor_sem){++++}-{3:3}: down_read+0x9a/0x330 kernel/locking/rwsem.c:1526 nilfs_transaction_begin+0x329/0xa40 fs/nilfs2/segment.c:223 nilfs_symlink+0x130/0x3e0 fs/nilfs2/namei.c:140 vfs_symlink fs/namei.c:4464 [inline] vfs_symlink+0x3e4/0x620 fs/namei.c:4448 do_symlinkat+0x25f/0x310 fs/namei.c:4490 __do_sys_symlinkat fs/namei.c:4506 [inline] __se_sys_symlinkat fs/namei.c:4503 [inline] __ia32_sys_symlinkat+0x97/0xc0 fs/namei.c:4503 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x62/0xe0 arch/x86/entry/common.c:321 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x70/0x7a -> #0 (sb_internal#4){.+.+}-{0:0}: 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+0x2433/0x3b20 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5719 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1635 [inline] sb_start_intwrite include/linux/fs.h:1757 [inline] nilfs_transaction_begin+0x21e/0xa40 fs/nilfs2/segment.c:220 nilfs_dirty_inode+0x1a0/0x270 fs/nilfs2/inode.c:1158 __mark_inode_dirty+0x1e0/0xd60 fs/fs-writeback.c:2452 mark_inode_dirty_sync include/linux/fs.h:2311 [inline] iput.part.0+0x5b/0x7b0 fs/inode.c:1800 iput+0x5c/0x80 fs/inode.c:1793 dentry_unlink_inode+0x292/0x430 fs/dcache.c:401 __dentry_kill+0x3b8/0x640 fs/dcache.c:607 shrink_dentry_list+0x11e/0x4a0 fs/dcache.c:1201 prune_dcache_sb+0xeb/0x150 fs/dcache.c:1282 super_cache_scan+0x327/0x540 fs/super.c:228 do_shrink_slab+0x428/0x1120 mm/shrinker.c:435 shrink_slab_memcg mm/shrinker.c:548 [inline] shrink_slab+0xa83/0x1310 mm/shrinker.c:626 shrink_one+0x47d/0x7a0 mm/vmscan.c:4745 shrink_many mm/vmscan.c:4808 [inline] lru_gen_shrink_node mm/vmscan.c:4923 [inline] shrink_node+0x211c/0x3710 mm/vmscan.c:5863 kswapd_shrink_node mm/vmscan.c:6668 [inline] balance_pgdat+0x9d2/0x1a90 mm/vmscan.c:6858 kswapd+0x5be/0xbf0 mm/vmscan.c:7118 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 other info that might help us debug this: Chain exists of: sb_internal#4 --> &nilfs->ns_segctor_sem --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&nilfs->ns_segctor_sem); lock(fs_reclaim); rlock(sb_internal#4); *** DEADLOCK *** 2 locks held by kswapd0/108: #0: ffffffff8d11c740 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x160/0x1a90 mm/vmscan.c:6746 #1: ffff8880799540e0 (&type->s_umount_key#68){++++}-{3:3}, at: super_trylock_shared fs/super.c:610 [inline] #1: ffff8880799540e0 (&type->s_umount_key#68){++++}-{3:3}, at: super_cache_scan+0x96/0x540 fs/super.c:203 stack backtrace: CPU: 2 PID: 108 Comm: kswapd0 Not tainted 6.7.0-rc6-syzkaller-00022-g55cb5f43689d #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+0xd9/0x1b0 lib/dump_stack.c:106 check_noncircular+0x317/0x400 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+0x2433/0x3b20 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5719 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1635 [inline] sb_start_intwrite include/linux/fs.h:1757 [inline] nilfs_transaction_begin+0x21e/0xa40 fs/nilfs2/segment.c:220 nilfs_dirty_inode+0x1a0/0x270 fs/nilfs2/inode.c:1158 __mark_inode_dirty+0x1e0/0xd60 fs/fs-writeback.c:2452 mark_inode_dirty_sync include/linux/fs.h:2311 [inline] iput.part.0+0x5b/0x7b0 fs/inode.c:1800 iput+0x5c/0x80 fs/inode.c:1793 dentry_unlink_inode+0x292/0x430 fs/dcache.c:401 __dentry_kill+0x3b8/0x640 fs/dcache.c:607 shrink_dentry_list+0x11e/0x4a0 fs/dcache.c:1201 prune_dcache_sb+0xeb/0x150 fs/dcache.c:1282 super_cache_scan+0x327/0x540 fs/super.c:228 do_shrink_slab+0x428/0x1120 mm/shrinker.c:435 shrink_slab_memcg mm/shrinker.c:548 [inline] shrink_slab+0xa83/0x1310 mm/shrinker.c:626 shrink_one+0x47d/0x7a0 mm/vmscan.c:4745 shrink_many mm/vmscan.c:4808 [inline] lru_gen_shrink_node mm/vmscan.c:4923 [inline] shrink_node+0x211c/0x3710 mm/vmscan.c:5863 kswapd_shrink_node mm/vmscan.c:6668 [inline] balance_pgdat+0x9d2/0x1a90 mm/vmscan.c:6858 kswapd+0x5be/0xbf0 mm/vmscan.c:7118 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 </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@xxxxxxxxxxxxxxxx. 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
