syzbot


KASAN: slab-out-of-bounds Write in vmac_final

Status: fixed on 2018/08/28 17:48
Subsystems: crypto
[Documentation on labels]
Reported-by: syzbot+264bca3a6e8d645550d3@syzkaller.appspotmail.com
Fix commit: bb2964810233 crypto: vmac - separate tfm and request context
First crash: 2139d, last: 2138d
Discussions (8)
Title Replies (including bot) Last reply
[PATCH 3.16 000/328] 3.16.62-rc1 review 338 (338) 2018/12/16 22:01
[PATCH 4.4 00/13] 4.4.149-stable review 16 (16) 2018/08/18 15:30
[PATCH 4.18 00/22] 4.18.2-stable review 27 (27) 2018/08/18 15:22
[PATCH 4.9 00/15] 4.9.121-stable review 19 (19) 2018/08/18 15:08
[PATCH 4.14 00/22] 4.14.64-stable review 23 (23) 2018/08/18 14:36
[PATCH 4.17 00/21] 4.17.16-stable review 24 (24) 2018/08/18 14:05
[PATCH 3.18 00/15] 3.18.119-stable review 21 (21) 2018/08/17 17:16
KASAN: slab-out-of-bounds Write in vmac_final 1 (2) 2018/06/16 15:36

Sample crash report:
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
==================================================================
------------[ cut here ]------------
BUG: KASAN: slab-out-of-bounds in memset include/linux/string.h:330 [inline]
BUG: KASAN: slab-out-of-bounds in vmac_final+0x161/0x26a0 crypto/vmac.c:611
ODEBUG: deactivate not available (active state 0) object type: timer_list hint: process_timeout+0x0/0x40 kernel/time/timer.c:1423
Write of size 18446744073709551516 at addr ffff8801cef677cc by task syz-executor217/6484
WARNING: CPU: 0 PID: 6468 at lib/debugobjects.c:329 debug_print_object+0x16a/0x210 lib/debugobjects.c:326

Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 6484 Comm: syz-executor217 Not tainted 4.17.0+ #98
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 memset+0x23/0x40 mm/kasan/kasan.c:285
 memset include/linux/string.h:330 [inline]
 vmac_final+0x161/0x26a0 crypto/vmac.c:611
 crypto_shash_final+0x104/0x260 crypto/shash.c:152
 shash_async_final+0x35/0x40 crypto/shash.c:252
 crypto_ahash_op+0xcf/0x180 crypto/ahash.c:362
 crypto_ahash_final+0x57/0x70 crypto/ahash.c:367
 hash_sendmsg+0x750/0xac0 crypto/algif_hash.c:126
 sock_sendmsg_nosec net/socket.c:645 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:655
 ___sys_sendmsg+0x805/0x940 net/socket.c:2161
 __sys_sendmsg+0x115/0x270 net/socket.c:2199
 __do_sys_sendmsg net/socket.c:2208 [inline]
 __se_sys_sendmsg net/socket.c:2206 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2206
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446af9
Code: e8 4c e7 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 4b 56 00 00 c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007f4c7cca3ce8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000006dcc5c RCX: 0000000000446af9
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000008
RBP: 00000000006dcc58 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff3230487f R14: 00007f4c7cca49c0 R15: 000000000000000b

CPU: 0 PID: 6468 Comm: syz-executor217 Not tainted 4.17.0+ #98
Allocated by task 6468:
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
Call Trace:
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 <IRQ>
 __do_kmalloc mm/slab.c:3718 [inline]
 __kmalloc+0x14e/0x760 mm/slab.c:3727
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 kmalloc include/linux/slab.h:518 [inline]
 kzalloc include/linux/slab.h:706 [inline]
 crypto_create_tfm+0x87/0x310 crypto/api.c:464
 crypto_init_shash_ops_async+0x5d/0x3e4 crypto/shash.c:357
 crypto_ahash_init_tfm+0x357/0x430 crypto/ahash.c:458
 panic+0x22f/0x4de kernel/panic.c:184
 crypto_create_tfm+0xe9/0x310 crypto/api.c:471
 crypto_alloc_tfm+0x1b5/0x2d0 crypto/api.c:543
 crypto_alloc_ahash+0x2c/0x40 crypto/ahash.c:539
 hash_bind+0x25/0x30 crypto/algif_hash.c:408
 alg_bind+0x2be/0x560 crypto/af_alg.c:183
 __sys_bind+0x331/0x440 net/socket.c:1528
 __warn.cold.8+0x163/0x1b3 kernel/panic.c:536
 __do_sys_bind net/socket.c:1539 [inline]
 __se_sys_bind net/socket.c:1537 [inline]
 __x64_sys_bind+0x73/0xb0 net/socket.c:1537
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290
 report_bug+0x252/0x2d0 lib/bug.c:186
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1fc/0x4d0 arch/x86/kernel/traps.c:296
Freed by task 3238:
(stack is not available)

The buggy address belongs to the object at ffff8801cef675c0
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 12 bytes to the right of
 512-byte region [ffff8801cef675c0, ffff8801cef677c0)
The buggy address belongs to the page:
page:ffffea00073bd9c0 count:1 mapcount:0 mapping:ffff8801da800940 index:0x0
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
flags: 0x2fffc0000000100(slab)
RIP: 0010:debug_print_object+0x16a/0x210 lib/debugobjects.c:326
raw: 02fffc0000000100 ffffea00073bd848 ffffea00073a4748 ffff8801da800940
Code: 
raw: 0000000000000000 ffff8801cef670c0 0000000100000006 0000000000000000
1a 
page dumped because: kasan: bad access detected
88 

48 
Memory state around the buggy address:
89 
 ffff8801cef67680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
fa 
 ffff8801cef67700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
48 
>ffff8801cef67780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
c1 
                                              ^
ea 03 
 ffff8801cef67800: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
80 
 ffff8801cef67880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
3c 
==================================================================
02 00 0f 85 92 00 00 00 48 8b 14 dd 20 7a 1a 88 4c 89 f6 48 c7 c7 a0 6f 1a 88 e8 a6 4d ec fd <0f> 0b 83 05 19 4c 44 06 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 
kasan: CONFIG_KASAN_INLINE enabled
RSP: 0018:ffff8801dae07850 EFLAGS: 00010086
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
RAX: 0000000000000068 RBX: 0000000000000005 RCX: ffffffff81854ed8
CPU: 1 PID: 0 Comm:  Tainted: G    B             4.17.0+ #98
RDX: 0000000000000100 RSI: ffffffff8161f371 RDI: 0000000000000001
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RBP: ffff8801dae07890 R08: ffff8801d2e38280 R09: ffffed003b5c3ec2
R10: ffffed003b5c3ec2 R11: ffff8801dae1f617 R12: 0000000000000001
RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline]
RIP: 0010:get_running_cputimer include/linux/sched/cputime.h:85 [inline]
RIP: 0010:account_group_system_time include/linux/sched/cputime.h:149 [inline]
RIP: 0010:account_system_index_time+0xea/0x5b0 kernel/sched/cputime.c:168
R13: ffffffff88f9a940 R14: ffffffff881a7380 R15: ffffffff81677180
Code: 
63 
04 
00 
 debug_object_deactivate+0x2a7/0x400 lib/debugobjects.c:563
00 
48 8b 
83 
b8 
 debug_timer_deactivate kernel/time/timer.c:714 [inline]
 debug_deactivate kernel/time/timer.c:770 [inline]
 detach_timer kernel/time/timer.c:815 [inline]
 expire_timers kernel/time/timer.c:1353 [inline]
 __run_timers+0x569/0xc50 kernel/time/timer.c:1666
06 
00 
00 
48 
ba 
00 
00 
00 00 
00 
fc 
ff 
 run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692
df 
 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:284
48 
8d b8 
38 
01 
00 00 
48 
8d 
88 20 
01 00 
00 
 invoke_softirq kernel/softirq.c:364 [inline]
 irq_exit+0x1d1/0x200 kernel/softirq.c:404
48 89 
 exiting_irq arch/x86/include/asm/apic.h:527 [inline]
 smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052
fe 
48 
c1 
ee 
03 <0f> 
b6 14 
16 
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
48 
 </IRQ>
89 
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:65
fe 
Code: 
83 
c1 
e6 
e9 
07 40 
03 40 
38 
0f 
f2 
b6 
7f 08 
f6 
84 d2 
48 
0f 
b8 
85 
01 
f6 
01 
03 
01 01 
00 
01 
RSP: 0018:ffff8801daf07980 EFLAGS: 00010006
01 01 
01 
RAX: 0000000000000000 RBX: ffff8801d0bce680 RCX: 0000000000000120
48 
RDX: dffffc0000000000 RSI: 0000000000000027 RDI: 0000000000000138
0f 
RBP: ffff8801daf07a68 R08: ffff8801d0bce680 R09: 0000000000000000
af c6 
R10: ffffed0043fff009 R11: ffff88021fff8057 R12: ffff8801daf07a40
f3 48 
R13: ffff8801d0bce680 R14: 00000000000f4240 R15: 0000000000000002
ab 
FS:  00007f4c7cca4700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
89 
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
d1 f3 
CR2: 0000000020000080 CR3: 00000001adf27000 CR4: 00000000001406e0
aa 
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
4c 89 c8 
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
c3 90 
 <IRQ>
49 
89 
f9 
40 
88 f0 
48 
89 d1 
 account_system_time+0x7f/0xb0 kernel/sched/cputime.c:199
<f3> 
 account_process_tick+0x76/0x240 kernel/sched/cputime.c:498
aa 
4c 89 
 update_process_times+0x21/0x70 kernel/time/timer.c:1634
c8 
 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
c3 90 
 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
49 
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1460
89 
fa 40 
0f 
b6 
ce 
48 b8 
01 
01 01 
01 01 
01 
RSP: 0018:ffff8801d24d77f0 EFLAGS: 00010282
 ORIG_RAX: ffffffffffffff13
 hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
RAX: 0000000000000000 RBX: ffff8801cef677cc RCX: ffffffffffc16593
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
 smp_apic_timer_interrupt+0x15d/0x710 arch/x86/kernel/apic/apic.c:1050
RDX: ffffffffffffff9c RSI: 0000000000000000 RDI: ffff8801cf3511d5
RBP: ffff8801d24d7810 R08: ffffed0039deceed R09: ffff8801cef677cc
R10: ffffed0039deceec R11: ffff8801cef67767 R12: ffffffffffffff9c
R13: 0000000000000000 R14: ffff8801cef675c0 R15: ffff8801cef676e8
 memset include/linux/string.h:330 [inline]
 vmac_final+0x161/0x26a0 crypto/vmac.c:611
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
 </IRQ>
Modules linked in:
 crypto_shash_final+0x104/0x260 crypto/shash.c:152
Dumping ftrace buffer:
   (ftrace buffer empty)
---[ end trace 6543079521a07167 ]---
 shash_async_final+0x35/0x40 crypto/shash.c:252
RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline]
RIP: 0010:get_running_cputimer include/linux/sched/cputime.h:85 [inline]
RIP: 0010:account_group_system_time include/linux/sched/cputime.h:149 [inline]
RIP: 0010:account_system_index_time+0xea/0x5b0 kernel/sched/cputime.c:168
 crypto_ahash_op+0xcf/0x180 crypto/ahash.c:362
Code: 
 crypto_ahash_final+0x57/0x70 crypto/ahash.c:367
63 
 hash_sendmsg+0x750/0xac0 crypto/algif_hash.c:126
04 
 hash_sendmsg_nokey+0x61/0x80 crypto/algif_hash.c:346
00 
00 
 sock_sendmsg_nosec net/socket.c:645 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:655
48 
 __sys_sendto+0x3d7/0x670 net/socket.c:1833
8b 
83 b8 
06 
00 00 
48 
ba 
00 
00 00 
00 
00 
fc 
 __do_sys_sendto net/socket.c:1845 [inline]
 __se_sys_sendto net/socket.c:1841 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1841
ff 
df 
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290
48 
8d 
b8 
38 
01 
00 
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
00 
RIP: 0033:0x446af9
48 8d 
Code: 
88 20 
e8 
01 
4c 
00 
e7 ff 
00 
ff 
48 
48 
89 
83 
fe 
c4 18 
48 
c3 0f 
c1 
1f 
ee 
80 
03 <0f> 
00 
b6 
00 
14 
00 
16 
00 
48 
48 
89 fe 
89 f8 
83 
48 
e6 
89 
07 
f7 
40 
48 89 
38 
d6 
f2 
48 89 
7f 08 
ca 
84 
4d 
d2 
89 c2 
0f 85 
4d 
f6 
89 
03 00 
c8 
4c 8b 
RSP: 0018:ffff8801daf07980 EFLAGS: 00010006
4c 24 
08 
RAX: 0000000000000000 RBX: ffff8801d0bce680 RCX: 0000000000000120
0f 05 
RDX: dffffc0000000000 RSI: 0000000000000027 RDI: 0000000000000138
RBP: ffff8801daf07a68 R08: ffff8801d0bce680 R09: 0000000000000000
<48> 
R10: ffffed0043fff009 R11: ffff88021fff8057 R12: ffff8801daf07a40
3d 
R13: ffff8801d0bce680 R14: 00000000000f4240 R15: 0000000000000002
01 f0 
FS:  00007f4c7cca4700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
ff ff 
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
0f 83 
CR2: 0000000020000080 CR3: 00000001adf27000 CR4: 00000000001406e0
4b 
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
56 
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
00 00 c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007f4c7ccc4cd8 EFLAGS: 00000216 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00000000006dcc44 RCX: 0000000000446af9
RDX: 00000000000000f9 RSI: 0000000020000380 RDI: 0000000000000007
RBP: 00000000006dcc40 R08: 0000000020000480 R09: 0000000000000010
R10: 0000000000000804 R11: 0000000000000216 R12: 0000000000000000
R13: 00007fff3230487f R14: 00007f4c7ccc59c0 R15: 000000000000000b

======================================================
WARNING: possible circular locking dependency detected
4.17.0+ #98 Not tainted
------------------------------------------------------
syz-executor217/6468 is trying to acquire lock:
(____ptrval____) ((console_sem).lock){-.-.}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136

but task is already holding lock:
(____ptrval____) (&obj_hash[i].lock){-.-.}, at: debug_object_deactivate+0xe1/0x400 lib/debugobjects.c:538

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&obj_hash[i].lock){-.-.}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
       __debug_object_init+0x11f/0x12c0 lib/debugobjects.c:381
       debug_object_init+0x16/0x20 lib/debugobjects.c:429
       debug_hrtimer_init kernel/time/hrtimer.c:410 [inline]
       debug_init kernel/time/hrtimer.c:458 [inline]
       hrtimer_init+0x8f/0x460 kernel/time/hrtimer.c:1308
       init_dl_task_timer+0x1b/0x50 kernel/sched/deadline.c:1056
       __sched_fork+0x2a8/0x570 kernel/sched/core.c:2184
       init_idle+0x75/0x7a0 kernel/sched/core.c:5404
       sched_init+0xbeb/0xd10 kernel/sched/core.c:6102
       start_kernel+0x475/0x92d init/main.c:602
       x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:452
       x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:433
       secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242

-> #2 (&rq->lock){-.-.}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144
       rq_lock kernel/sched/sched.h:1805 [inline]
       task_fork_fair+0x8a/0x660 kernel/sched/fair.c:9953
       sched_fork+0x43e/0xb30 kernel/sched/core.c:2380
       copy_process.part.38+0x1bf1/0x7180 kernel/fork.c:1765
       copy_process kernel/fork.c:1608 [inline]
       _do_fork+0x291/0x12a0 kernel/fork.c:2091
       kernel_thread+0x34/0x40 kernel/fork.c:2150
       rest_init+0x22/0xe4 init/main.c:408
       start_kernel+0x906/0x92d init/main.c:738
       x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:452
       x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:433
       secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242

-> #1 (&p->pi_lock){-.-.}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
       try_to_wake_up+0xca/0x1280 kernel/sched/core.c:1984
       wake_up_process+0x10/0x20 kernel/sched/core.c:2147
       __up.isra.1+0x1b8/0x290 kernel/locking/semaphore.c:262
       up+0x12f/0x1b0 kernel/locking/semaphore.c:187
       __up_console_sem+0xbe/0x1b0 kernel/printk/printk.c:242
       console_unlock+0x79a/0x10a0 kernel/printk/printk.c:2411
       vprintk_emit+0x6b2/0xde0 kernel/printk/printk.c:1907
       vprintk_default+0x28/0x30 kernel/printk/printk.c:1948
       vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:382
       printk+0x9e/0xba kernel/printk/printk.c:1981
       load_umh+0x51/0xbd net/bpfilter/bpfilter_kern.c:99
       do_one_initcall+0x127/0x913 init/main.c:884
       do_initcall_level init/main.c:952 [inline]
       do_initcalls init/main.c:960 [inline]
       do_basic_setup init/main.c:978 [inline]
       kernel_init_freeable+0x49b/0x58e init/main.c:1135
       kernel_init+0x11/0x1b3 init/main.c:1061
       ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412

-> #0 ((console_sem).lock){-.-.}:
       lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3924
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
       down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
       __down_trylock_console_sem+0xae/0x200 kernel/printk/printk.c:225
       console_trylock+0x15/0xa0 kernel/printk/printk.c:2230
       console_trylock_spinning kernel/printk/printk.c:1643 [inline]
       vprintk_emit+0x699/0xde0 kernel/printk/printk.c:1906
       vprintk_default+0x28/0x30 kernel/printk/printk.c:1948
       vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:382
       printk+0x9e/0xba kernel/printk/printk.c:1981
       __warn_printk+0x83/0xd0 kernel/panic.c:590
       debug_print_object+0x16a/0x210 lib/debugobjects.c:326
       debug_object_deactivate+0x2a7/0x400 lib/debugobjects.c:563
       debug_timer_deactivate kernel/time/timer.c:714 [inline]
       debug_deactivate kernel/time/timer.c:770 [inline]
       detach_timer kernel/time/timer.c:815 [inline]
       expire_timers kernel/time/timer.c:1353 [inline]
       __run_timers+0x569/0xc50 kernel/time/timer.c:1666
       run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692
       __do_softirq+0x2e0/0xaf5 kernel/softirq.c:284
       invoke_softirq kernel/softirq.c:364 [inline]
       irq_exit+0x1d1/0x200 kernel/softirq.c:404
       exiting_irq arch/x86/include/asm/apic.h:527 [inline]
       smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052
       apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
       memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:65
       memset include/linux/string.h:330 [inline]
       vmac_final+0x161/0x26a0 crypto/vmac.c:611
       crypto_shash_final+0x104/0x260 crypto/shash.c:152
       shash_async_final+0x35/0x40 crypto/shash.c:252
       crypto_ahash_op+0xcf/0x180 crypto/ahash.c:362
       crypto_ahash_final+0x57/0x70 crypto/ahash.c:367
       hash_sendmsg+0x750/0xac0 crypto/algif_hash.c:126
       hash_sendmsg_nokey+0x61/0x80 crypto/algif_hash.c:346
       sock_sendmsg_nosec net/socket.c:645 [inline]
       sock_sendmsg+0xd5/0x120 net/socket.c:655
       __sys_sendto+0x3d7/0x670 net/socket.c:1833
       __do_sys_sendto net/socket.c:1845 [inline]
       __se_sys_sendto net/socket.c:1841 [inline]
       __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1841
       do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

other info that might help us debug this:

Chain exists of:
  (console_sem).lock --> &rq->lock --> &obj_hash[i].lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&obj_hash[i].lock);
                               lock(&rq->lock);
                               lock(&obj_hash[i].lock);
  lock((console_sem).lock);

 *** DEADLOCK ***

3 locks held by syz-executor217/6468:
 #0: (____ptrval____) (sk_lock-AF_ALG){+.+.}, at: lock_sock include/net/sock.h:1474 [inline]
 #0: (____ptrval____) (sk_lock-AF_ALG){+.+.}, at: hash_sendmsg+0xd9/0xac0 crypto/algif_hash.c:81
 #1: (____ptrval____) (&base->lock){-.-.}, at: __run_timers+0x16e/0xc50 kernel/time/timer.c:1658
 #2: (____ptrval____) (&obj_hash[i].lock){-.-.}, at: debug_object_deactivate+0xe1/0x400 lib/debugobjects.c:538

stack backtrace:
CPU: 0 PID: 6468 Comm: syz-executor217 Not tainted 4.17.0+ #98
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+0x1b9/0x294 lib/dump_stack.c:113
 print_circular_bug.isra.36.cold.56+0x1bd/0x27d kernel/locking/lockdep.c:1227
 check_prev_add kernel/locking/lockdep.c:1867 [inline]
 check_prevs_add kernel/locking/lockdep.c:1980 [inline]
 validate_chain kernel/locking/lockdep.c:2421 [inline]
 __lock_acquire+0x343e/0x5140 kernel/locking/lockdep.c:3435
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3924
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
 __down_trylock_console_sem+0xae/0x200 kernel/printk/printk.c:225
 console_trylock+0x15/0xa0 kernel/printk/printk.c:2230
 console_trylock_spinning kernel/printk/printk.c:1643 [inline]
 vprintk_emit+0x699/0xde0 kernel/printk/printk.c:1906
 vprintk_default+0x28/0x30 kernel/printk/printk.c:1948
 vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:382
 printk+0x9e/0xba kernel/printk/printk.c:1981
 __warn_printk+0x83/0xd0 kernel/panic.c:590
 debug_print_object+0x16a/0x210 lib/debugobjects.c:326
 debug_object_deactivate+0x2a7/0x400 lib/debugobjects.c:563
 debug_timer_deactivate kernel/time/timer.c:714 [inline]
 debug_deactivate kernel/time/timer.c:770 [inline]
 detach_timer kernel/time/timer.c:815 [inline]
 expire_timers kernel/time/timer.c:1353 [inline]
 __run_timers+0x569/0xc50 kernel/time/timer.c:1666
 run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692
 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:284
 invoke_softirq kernel/softirq.c:364 [inline]
 irq_exit+0x1d1/0x200 kernel/softirq.c:404
 exiting_irq arch/x86/include/asm/apic.h:527 [inline]
 smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
 </IRQ>
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:65
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 
RSP: 0018:ffff8801d24d77f0 EFLAGS: 00010282 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff8801cef677cc RCX: ffffffffffc16593
RDX: ffffffffffffff9c RSI: 0000000000000000 RDI: ffff8801cf3511d5
RBP: ffff8801d24d7810 R08: ffffed0039deceed R09: ffff8801cef677cc
R10: ffffed0039deceec R11: ffff8801cef67767 R12: ffffffffffffff9c
R13: 0000000000000000 R14: ffff8801cef675c0 R15: ffff8801cef676e8
 memset include/linux/string.h:330 [inline]
 vmac_final+0x161/0x26a0 crypto/vmac.c:611
 crypto_shash_final+0x104/0x260 crypto/shash.c:152
 shash_async_final+0x35/0x40 crypto/shash.c:252
 crypto_ahash_op+0xcf/0x180 crypto/ahash.c:362
 crypto_ahash_final+0x57/0x70 crypto/ahash.c:367
 hash_sendmsg+0x750/0xac0 crypto/algif_hash.c:126
 hash_sendmsg_nokey+0x61/0x80 crypto/algif_hash.c:346
Lost 95 message(s)!
Shutting down cpus with NMI
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/06/12 13:30 upstream 8efcf34a2639 112eec79 .config console log report syz C ci-upstream-kasan-gce-root
2018/06/12 09:25 upstream 8efcf34a2639 112eec79 .config console log report syz C ci-upstream-kasan-gce
* Struck through repros no longer work on HEAD.