loop0: detected capacity change from 0 to 8 ====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc1-syzkaller-00042-gf23aa4c0761a #0 Not tainted ------------------------------------------------------ syz.0.0/5111 is trying to acquire lock: ffff88803de77130 (&group->mark_mutex){+.+.}-{3:3}, at: fsnotify_group_lock include/linux/fsnotify_backend.h:270 [inline] ffff88803de77130 (&group->mark_mutex){+.+.}-{3:3}, at: fsnotify_destroy_mark+0x38/0x3c0 fs/notify/mark.c:578 but task is already holding lock: ffffffff8ea37160 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3907 [inline] ffffffff8ea37160 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim+0xd4/0x3d0 mm/page_alloc.c:3932 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:5825 __fs_reclaim_acquire mm/page_alloc.c:3834 [inline] fs_reclaim_acquire+0x88/0x140 mm/page_alloc.c:3848 might_alloc include/linux/sched/mm.h:327 [inline] slab_pre_alloc_hook mm/slub.c:4037 [inline] slab_alloc_node mm/slub.c:4115 [inline] kmem_cache_alloc_noprof+0x3d/0x2a0 mm/slub.c:4142 inotify_new_watch fs/notify/inotify/inotify_user.c:599 [inline] inotify_update_watch fs/notify/inotify/inotify_user.c:647 [inline] __do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:786 [inline] __se_sys_inotify_add_watch+0x728/0x1060 fs/notify/inotify/inotify_user.c:729 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 -> #0 (&group->mark_mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 fsnotify_group_lock include/linux/fsnotify_backend.h:270 [inline] fsnotify_destroy_mark+0x38/0x3c0 fs/notify/mark.c:578 fsnotify_destroy_marks+0x14a/0x660 fs/notify/mark.c:934 fsnotify_inoderemove include/linux/fsnotify.h:264 [inline] dentry_unlink_inode+0x2e0/0x430 fs/dcache.c:408 __dentry_kill+0x20d/0x630 fs/dcache.c:615 shrink_kill+0xa9/0x2c0 fs/dcache.c:1060 shrink_dentry_list+0x2c0/0x5b0 fs/dcache.c:1087 prune_dcache_sb+0x10f/0x180 fs/dcache.c:1168 super_cache_scan+0x34f/0x4b0 fs/super.c:221 do_shrink_slab+0x701/0x1160 mm/shrinker.c:435 shrink_slab+0x1093/0x14d0 mm/shrinker.c:662 shrink_one+0x43b/0x850 mm/vmscan.c:4818 shrink_many mm/vmscan.c:4879 [inline] lru_gen_shrink_node mm/vmscan.c:4957 [inline] shrink_node+0x3799/0x3de0 mm/vmscan.c:5937 shrink_zones mm/vmscan.c:6195 [inline] do_try_to_free_pages+0x78c/0x1cf0 mm/vmscan.c:6257 try_to_free_pages+0x9f0/0x10a0 mm/vmscan.c:6507 __perform_reclaim mm/page_alloc.c:3910 [inline] __alloc_pages_direct_reclaim+0x173/0x3d0 mm/page_alloc.c:3932 __alloc_pages_slowpath+0x764/0x1020 mm/page_alloc.c:4363 __alloc_pages_noprof+0x43e/0x6c0 mm/page_alloc.c:4746 __folio_alloc_noprof+0x18/0x210 mm/page_alloc.c:4765 alloc_buddy_hugetlb_folio+0xeb/0x450 mm/hugetlb.c:2024 alloc_fresh_hugetlb_folio+0x83/0x320 mm/hugetlb.c:2095 alloc_migrate_hugetlb_folio mm/hugetlb.c:2349 [inline] alloc_hugetlb_folio_nodemask+0x13e/0x370 mm/hugetlb.c:2431 alloc_migration_target_by_mpol+0x4c4/0x8b0 mm/mempolicy.c:1230 unmap_and_move_huge_page mm/migrate.c:1464 [inline] migrate_hugetlbs mm/migrate.c:1646 [inline] migrate_pages+0x63d/0x3560 mm/migrate.c:2044 do_mbind mm/mempolicy.c:1390 [inline] kernel_mbind mm/mempolicy.c:1533 [inline] __do_sys_mbind mm/mempolicy.c:1607 [inline] __se_sys_mbind+0x14a7/0x1a10 mm/mempolicy.c:1603 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 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&group->mark_mutex); lock(fs_reclaim); lock(&group->mark_mutex); *** DEADLOCK *** 2 locks held by syz.0.0/5111: #0: ffffffff8ea37160 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3907 [inline] #0: ffffffff8ea37160 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim+0xd4/0x3d0 mm/page_alloc.c:3932 #1: ffff8880316e40e0 (&type->s_umount_key#47){.+.+}-{3:3}, at: super_trylock_shared fs/super.c:562 [inline] #1: ffff8880316e40e0 (&type->s_umount_key#47){.+.+}-{3:3}, at: super_cache_scan+0x94/0x4b0 fs/super.c:196 stack backtrace: CPU: 0 UID: 0 PID: 5111 Comm: syz.0.0 Not tainted 6.12.0-rc1-syzkaller-00042-gf23aa4c0761a #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: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 fsnotify_group_lock include/linux/fsnotify_backend.h:270 [inline] fsnotify_destroy_mark+0x38/0x3c0 fs/notify/mark.c:578 fsnotify_destroy_marks+0x14a/0x660 fs/notify/mark.c:934 fsnotify_inoderemove include/linux/fsnotify.h:264 [inline] dentry_unlink_inode+0x2e0/0x430 fs/dcache.c:408 __dentry_kill+0x20d/0x630 fs/dcache.c:615 shrink_kill+0xa9/0x2c0 fs/dcache.c:1060 shrink_dentry_list+0x2c0/0x5b0 fs/dcache.c:1087 prune_dcache_sb+0x10f/0x180 fs/dcache.c:1168 super_cache_scan+0x34f/0x4b0 fs/super.c:221 do_shrink_slab+0x701/0x1160 mm/shrinker.c:435 shrink_slab+0x1093/0x14d0 mm/shrinker.c:662 shrink_one+0x43b/0x850 mm/vmscan.c:4818 shrink_many mm/vmscan.c:4879 [inline] lru_gen_shrink_node mm/vmscan.c:4957 [inline] shrink_node+0x3799/0x3de0 mm/vmscan.c:5937 shrink_zones mm/vmscan.c:6195 [inline] do_try_to_free_pages+0x78c/0x1cf0 mm/vmscan.c:6257 try_to_free_pages+0x9f0/0x10a0 mm/vmscan.c:6507 __perform_reclaim mm/page_alloc.c:3910 [inline] __alloc_pages_direct_reclaim+0x173/0x3d0 mm/page_alloc.c:3932 __alloc_pages_slowpath+0x764/0x1020 mm/page_alloc.c:4363 __alloc_pages_noprof+0x43e/0x6c0 mm/page_alloc.c:4746 __folio_alloc_noprof+0x18/0x210 mm/page_alloc.c:4765 alloc_buddy_hugetlb_folio+0xeb/0x450 mm/hugetlb.c:2024 alloc_fresh_hugetlb_folio+0x83/0x320 mm/hugetlb.c:2095 alloc_migrate_hugetlb_folio mm/hugetlb.c:2349 [inline] alloc_hugetlb_folio_nodemask+0x13e/0x370 mm/hugetlb.c:2431 alloc_migration_target_by_mpol+0x4c4/0x8b0 mm/mempolicy.c:1230 unmap_and_move_huge_page mm/migrate.c:1464 [inline] migrate_hugetlbs mm/migrate.c:1646 [inline] migrate_pages+0x63d/0x3560 mm/migrate.c:2044 do_mbind mm/mempolicy.c:1390 [inline] kernel_mbind mm/mempolicy.c:1533 [inline] __do_sys_mbind mm/mempolicy.c:1607 [inline] __se_sys_mbind+0x14a7/0x1a10 mm/mempolicy.c:1603 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: 0033:0x7f676317dff9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007f6763f51038 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed RAX: ffffffffffffffda RBX: 00007f6763335f80 RCX: 00007f676317dff9 RDX: 0000000000000000 RSI: 0000000000004000 RDI: 0000000020d44000 RBP: 00007f67631f0296 R08: 0000000000000000 R09: 0000000000000002 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6763335f80 R15: 00007ffcffdcbc88