====================================================== WARNING: possible circular locking dependency detected 6.11.0-syzkaller-04557-g2f27fce67173 #0 Not tainted ------------------------------------------------------ kswapd0/79 is trying to acquire lock: ffff88803c9e2e98 (&type->lock_class){+.+.}-{3:3}, at: keyring_clear+0xb2/0x350 security/keys/keyring.c:1655 but task is already holding lock: ffffffff8ea30460 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6821 [inline] ffffffff8ea30460 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbf1/0x3720 mm/vmscan.c:7203 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:5822 __fs_reclaim_acquire mm/page_alloc.c:3825 [inline] fs_reclaim_acquire+0x88/0x140 mm/page_alloc.c:3839 might_alloc include/linux/sched/mm.h:334 [inline] slab_pre_alloc_hook mm/slub.c:3940 [inline] slab_alloc_node mm/slub.c:4018 [inline] __kmalloc_cache_noprof+0x3d/0x2c0 mm/slub.c:4185 kmalloc_noprof include/linux/slab.h:690 [inline] kzalloc_noprof include/linux/slab.h:816 [inline] assoc_array_insert+0xfe/0x33e0 lib/assoc_array.c:980 __key_link_begin+0xe5/0x1f0 security/keys/keyring.c:1314 __key_create_or_update+0x570/0xc70 security/keys/key.c:874 key_create_or_update+0x42/0x60 security/keys/key.c:1018 x509_load_certificate_list+0x149/0x270 crypto/asymmetric_keys/x509_loader.c:31 do_one_initcall+0x248/0x880 init/main.c:1269 do_initcall_level+0x157/0x210 init/main.c:1331 do_initcalls+0x3f/0x80 init/main.c:1347 kernel_init_freeable+0x435/0x5d0 init/main.c:1580 kernel_init+0x1d/0x2b0 init/main.c:1469 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (&type->lock_class){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3158 [inline] check_prevs_add kernel/locking/lockdep.c:3277 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3901 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5199 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822 down_write+0x99/0x220 kernel/locking/rwsem.c:1579 keyring_clear+0xb2/0x350 security/keys/keyring.c:1655 fscrypt_put_master_key+0xc8/0x190 fs/crypto/keyring.c:79 put_crypt_info+0x275/0x320 fs/crypto/keysetup.c:548 fscrypt_put_encryption_info+0x40/0x60 fs/crypto/keysetup.c:753 ext4_clear_inode+0x15b/0x1c0 fs/ext4/super.c:1524 ext4_evict_inode+0xabc/0xf50 fs/ext4/inode.c:318 evict+0x4e8/0x9b0 fs/inode.c:731 __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:4795 shrink_many mm/vmscan.c:4856 [inline] lru_gen_shrink_node mm/vmscan.c:4934 [inline] shrink_node+0x3799/0x3de0 mm/vmscan.c:5914 kswapd_shrink_node mm/vmscan.c:6742 [inline] balance_pgdat mm/vmscan.c:6934 [inline] kswapd+0x1cbc/0x3720 mm/vmscan.c:7203 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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(&type->lock_class); lock(fs_reclaim); lock(&type->lock_class); *** DEADLOCK *** 2 locks held by kswapd0/79: #0: ffffffff8ea30460 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6821 [inline] #0: ffffffff8ea30460 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbf1/0x3720 mm/vmscan.c:7203 #1: ffff88803ba840e0 (&type->s_umount_key#32){++++}-{3:3}, at: super_trylock_shared fs/super.c:562 [inline] #1: ffff88803ba840e0 (&type->s_umount_key#32){++++}-{3:3}, at: super_cache_scan+0x94/0x4b0 fs/super.c:196 stack backtrace: CPU: 0 UID: 0 PID: 79 Comm: kswapd0 Not tainted 6.11.0-syzkaller-04557-g2f27fce67173 #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:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2203 check_prev_add kernel/locking/lockdep.c:3158 [inline] check_prevs_add kernel/locking/lockdep.c:3277 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3901 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5199 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822 down_write+0x99/0x220 kernel/locking/rwsem.c:1579 keyring_clear+0xb2/0x350 security/keys/keyring.c:1655 fscrypt_put_master_key+0xc8/0x190 fs/crypto/keyring.c:79 put_crypt_info+0x275/0x320 fs/crypto/keysetup.c:548 fscrypt_put_encryption_info+0x40/0x60 fs/crypto/keysetup.c:753 ext4_clear_inode+0x15b/0x1c0 fs/ext4/super.c:1524 ext4_evict_inode+0xabc/0xf50 fs/ext4/inode.c:318 evict+0x4e8/0x9b0 fs/inode.c:731 __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:4795 shrink_many mm/vmscan.c:4856 [inline] lru_gen_shrink_node mm/vmscan.c:4934 [inline] shrink_node+0x3799/0x3de0 mm/vmscan.c:5914 kswapd_shrink_node mm/vmscan.c:6742 [inline] balance_pgdat mm/vmscan.c:6934 [inline] kswapd+0x1cbc/0x3720 mm/vmscan.c:7203 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244