============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- kworker/u32:7/1148 is trying to acquire lock: ffffe8fefc577ff8 (&pd_list->lock){+...}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] ffffe8fefc577ff8 (&pd_list->lock){+...}-{3:3}, at: padata_find_next kernel/padata.c:256 [inline] ffffe8fefc577ff8 (&pd_list->lock){+...}-{3:3}, at: padata_reorder kernel/padata.c:313 [inline] ffffe8fefc577ff8 (&pd_list->lock){+...}-{3:3}, at: padata_do_serial+0x7d7/0xda0 kernel/padata.c:383 but task is already holding lock: ffffe8fefc67d448 (&pd_list->lock){+...}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] ffffe8fefc67d448 (&pd_list->lock){+...}-{3:3}, at: padata_reorder kernel/padata.c:304 [inline] ffffe8fefc67d448 (&pd_list->lock){+...}-{3:3}, at: padata_do_serial+0x6b0/0xda0 kernel/padata.c:383 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&pd_list->lock); lock(&pd_list->lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by kworker/u32:7/1148: #0: ffff888023c2e148 ((wq_completion)pdecrypt_parallel){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc90005fc7d00 ((work_completion)(&pw->pw_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffe8fefc67d448 (&pd_list->lock){+...}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffffe8fefc67d448 (&pd_list->lock){+...}-{3:3}, at: padata_reorder kernel/padata.c:304 [inline] #2: ffffe8fefc67d448 (&pd_list->lock){+...}-{3:3}, at: padata_do_serial+0x6b0/0xda0 kernel/padata.c:383 stack backtrace: CPU: 2 UID: 0 PID: 1148 Comm: kworker/u32:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: pdecrypt_parallel padata_parallel_worker Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_deadlock_bug+0x1e9/0x240 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x1106/0x1c90 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] padata_find_next kernel/padata.c:256 [inline] padata_reorder kernel/padata.c:313 [inline] padata_do_serial+0x7d7/0xda0 kernel/padata.c:383 pcrypt_aead_dec+0x5b/0x70 crypto/pcrypt.c:140 padata_parallel_worker+0x65/0xb0 kernel/padata.c:157 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 netdevsim netdevsim3 eth3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim3 eth2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim3 eth1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim3 eth0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 bond1 (unregistering): (slave ip6erspan1): Releasing active interface bond0 (unregistering): Released all slaves bond1 (unregistering): Released all slaves bond2 (unregistering): Released all slaves hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode veth1_macvtap: left promiscuous mode veth0_macvtap: left promiscuous mode veth1_vlan: left promiscuous mode veth0_vlan: left promiscuous mode IPVS: stop unused estimator thread 0... bridge_slave_0: left allmulticast mode bridge_slave_0: left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): (slave bridge_slave_1): Releasing backup interface bond0 (unregistering): Released all slaves bond1 (unregistering): Released all slaves bond2 (unregistering): Released all slaves bond3 (unregistering): Released all slaves hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_1 batman_adv: batadv0: Removing interface: dummy0 batman_adv: batadv0: Removing interface: team0 team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed IPVS: stop unused estimator thread 0...