inconsistent lock state in ima_process_queued_keys

From: syzbot
Date: Tue Jan 14 2020 - 08:56:12 EST


Hello,

syzbot found the following crash on:

HEAD commit: 1b851f98 Add linux-next specific files for 20200114
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=12bcbb25e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=3e7d9cf7ebfa08ad
dashboard link: https://syzkaller.appspot.com/bug?extid=a4a503d7f37292ae1664
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

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-20200114-syzkaller #0 Not tainted
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
syz-executor.5/9563 [HC0[0]:SC1[1]:HE1:SE0] takes:
ffffffff8a03aa18 (ima_keys_lock){+.?.}, at: spin_lock include/linux/spinlock.h:338 [inline]
ffffffff8a03aa18 (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:940
do_initcall_level init/main.c:1014 [inline]
do_initcalls init/main.c:1022 [inline]
do_basic_setup init/main.c:1039 [inline]
kernel_init_freeable+0x4ca/0x570 init/main.c:1223
kernel_init+0x12/0x1bf init/main.c:1130
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
irq event stamp: 319180
hardirqs last enabled at (319180): [<ffffffff87ec3333>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
hardirqs last enabled at (319180): [<ffffffff87ec3333>] _raw_spin_unlock_irq+0x23/0x80 kernel/locking/spinlock.c:199
hardirqs last disabled at (319179): [<ffffffff87ec351a>] __raw_spin_lock_irq include/linux/spinlock_api_smp.h:126 [inline]
hardirqs last disabled at (319179): [<ffffffff87ec351a>] _raw_spin_lock_irq+0x3a/0x80 kernel/locking/spinlock.c:167
softirqs last enabled at (316932): [<ffffffff882006cd>] __do_softirq+0x6cd/0x98c kernel/softirq.c:319
softirqs last disabled at (319177): [<ffffffff8147800b>] invoke_softirq kernel/softirq.c:373 [inline]
softirqs last disabled at (319177): [<ffffffff8147800b>] 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 ***

1 lock held by syz-executor.5/9563:
#0: ffffc90000007d50 ((&ima_key_queue_timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:172 [inline]
#0: ffffc90000007d50 ((&ima_key_queue_timer)){+.-.}, at: call_timer_fn+0xe0/0x780 kernel/time/timer.c:1394

stack backtrace:
CPU: 0 PID: 9563 Comm: syz-executor.5 Not tainted 5.5.0-rc6-next-20200114-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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:slab_alloc mm/slab.c:3313 [inline]
RIP: 0010:kmem_cache_alloc+0x283/0x710 mm/slab.c:3484
Code: 7e 0f 85 dc fe ff ff e8 0c 3f 4d ff e9 d2 fe ff ff e8 31 aa c7 ff 48 83 3d 21 84 00 08 00 0f 84 51 03 00 00 48 8b 7d d0 57 9d <0f> 1f 44 00 00 e9 68 fe ff ff 31 d2 be 35 02 00 00 48 c7 c7 2e a1
RSP: 0018:ffffc9000641fd18 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000007 RBX: 0000000000000cc0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000286
RBP: ffffc9000641fd80 R08: ffff8880543b22c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880aa5f8a80
R13: ffff8880aa5f8a80 R14: 0000000000000cc0 R15: ffff8880a8916600
getname_flags fs/namei.c:138 [inline]
getname_flags+0xd6/0x5b0 fs/namei.c:128
getname fs/namei.c:209 [inline]
user_path_mountpoint_at+0x29/0x50 fs/namei.c:2820
ksys_umount+0x164/0xef0 fs/namespace.c:1683
__do_sys_umount fs/namespace.c:1709 [inline]
__se_sys_umount fs/namespace.c:1707 [inline]
__x64_sys_umount+0x54/0x80 fs/namespace.c:1707
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45d977
Code: 64 89 04 25 d0 02 00 00 58 5f ff d0 48 89 c7 e8 2f be ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 4d 8c fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffeff269038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 000000000004d5f3 RCX: 000000000045d977
RDX: 000000000000000c RSI: 0000000000000002 RDI: 00007ffeff26a170
RBP: 000000000000003c R08: 0000000000000001 R09: 0000000001dc6940
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffeff26a170
R13: 00007ffeff26a160 R14: 0000000000000000 R15: 00007ffeff26a170


---
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