syzbot has found a reproducer for the following crash on: HEAD commit: 2747d5fd Add linux-next specific files for 20200116 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=14ee1cc9e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=22f506e7a3a37fe2 dashboard link: https://syzkaller.appspot.com/bug?extid=a4a503d7f37292ae1664 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=128b4495e00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12b673b9e00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+a4a503d7f37292ae1664@xxxxxxxxxxxxxxxxxxxxxxxxx ================================ WARNING: inconsistent lock state 5.5.0-rc6-next-20200116-syzkaller #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. kworker/u4:3/125 [HC0[0]:SC1[1]:HE1:SE0] takes: ffffffff8a03ce58 (ima_keys_lock){+.?.}, at: spin_lock include/linux/spinlock.h:338 [inline] ffffffff8a03ce58 (ima_keys_lock){+.?.}, at: ima_process_queued_keys+0x4f/0x320 security/integrity/ima/ima_asymmetric_keys.c:144 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4484 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] ima_queue_key security/integrity/ima/ima_asymmetric_keys.c:111 [inline] ima_post_key_create_or_update+0x234/0x470 security/integrity/ima/ima_asymmetric_keys.c:194 key_create_or_update+0x6b8/0xcb0 security/keys/key.c:944 load_system_certificate_list+0x1ba/0x25e certs/system_keyring.c:161 do_one_initcall+0x120/0x820 init/main.c:1109 do_initcall_level init/main.c:1182 [inline] do_initcalls init/main.c:1198 [inline] do_basic_setup init/main.c:1218 [inline] kernel_init_freeable+0x522/0x5d0 init/main.c:1402 kernel_init+0x12/0x1bf init/main.c:1309 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 irq event stamp: 15703140 hardirqs last enabled at (15703140): [<ffffffff87ee0813>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] hardirqs last enabled at (15703140): [<ffffffff87ee0813>] _raw_spin_unlock_irq+0x23/0x80 kernel/locking/spinlock.c:199 hardirqs last disabled at (15703139): [<ffffffff87ee09fa>] __raw_spin_lock_irq include/linux/spinlock_api_smp.h:126 [inline] hardirqs last disabled at (15703139): [<ffffffff87ee09fa>] _raw_spin_lock_irq+0x3a/0x80 kernel/locking/spinlock.c:167 softirqs last enabled at (15702640): [<ffffffff87cf9855>] spin_unlock_bh include/linux/spinlock.h:383 [inline] softirqs last enabled at (15702640): [<ffffffff87cf9855>] batadv_nc_purge_paths+0x265/0x370 net/batman-adv/network-coding.c:470 softirqs last disabled at (15702651): [<ffffffff8147a05b>] invoke_softirq kernel/softirq.c:373 [inline] softirqs last disabled at (15702651): [<ffffffff8147a05b>] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(ima_keys_lock); <Interrupt> lock(ima_keys_lock); *** DEADLOCK *** 4 locks held by kworker/u4:3/125: #0: ffff88821512a928 ((wq_completion)bat_events){+.+.}, at: __write_once_size include/linux/compiler.h:250 [inline] #0: ffff88821512a928 ((wq_completion)bat_events){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88821512a928 ((wq_completion)bat_events){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:869 [inline] #0: ffff88821512a928 ((wq_completion)bat_events){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88821512a928 ((wq_completion)bat_events){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff88821512a928 ((wq_completion)bat_events){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff88821512a928 ((wq_completion)bat_events){+.+.}, at: process_one_work+0x8dd/0x17a0 kernel/workqueue.c:2235 #1: ffffc90001397dc0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}, at: process_one_work+0x917/0x17a0 kernel/workqueue.c:2239 #2: ffffffff89bb0400 (rcu_read_lock){....}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:405 [inline] #2: ffffffff89bb0400 (rcu_read_lock){....}, at: batadv_nc_worker+0xe3/0x760 net/batman-adv/network-coding.c:718 #3: ffffc90000d98d50 ((&ima_key_queue_timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:172 [inline] #3: ffffc90000d98d50 ((&ima_key_queue_timer)){+.-.}, at: call_timer_fn+0xe0/0x780 kernel/time/timer.c:1394 stack backtrace: CPU: 1 PID: 125 Comm: kworker/u4:3 Not tainted 5.5.0-rc6-next-20200116-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_usage_bug.cold+0x327/0x378 kernel/locking/lockdep.c:3100 valid_state kernel/locking/lockdep.c:3111 [inline] mark_lock_irq kernel/locking/lockdep.c:3308 [inline] mark_lock+0xbb4/0x1220 kernel/locking/lockdep.c:3665 mark_usage kernel/locking/lockdep.c:3565 [inline] __lock_acquire+0x1e8e/0x4a00 kernel/locking/lockdep.c:3908 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4484 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] ima_process_queued_keys+0x4f/0x320 security/integrity/ima/ima_asymmetric_keys.c:144 ima_timer_handler+0x15/0x20 security/integrity/ima/ima_asymmetric_keys.c:46 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0x6c3/0x1790 kernel/time/timer.c:1786 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 </IRQ> RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline] RIP: 0010:lock_acquire+0x20b/0x410 kernel/locking/lockdep.c:4487 Code: 9c 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 d3 01 00 00 48 83 3d 49 7d 58 08 00 0f 84 53 01 00 00 48 8b 7d c8 57 9d <0f> 1f 44 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 65 8b RSP: 0018:ffffc90001397c70 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff136774f RBX: ffff8880a922c600 RCX: ffffffff815ae240 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000286 RBP: ffffc90001397cb8 R08: 1ffffffff16a51a4 R09: fffffbfff16a51a5 R10: ffff8880a922cef0 R11: ffff8880a922c600 R12: ffffffff89bb0400 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002 rcu_lock_acquire include/linux/rcupdate.h:208 [inline] rcu_read_lock include/linux/rcupdate.h:601 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:407 [inline] batadv_nc_worker+0x117/0x760 net/batman-adv/network-coding.c:718 process_one_work+0xa05/0x17a0 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
