==================================================================
BUG: KASAN: alloca-out-of-bounds in tick_sched_handle+0x16d/0x180 kernel/time/tick-sched.c:171
Read of size 8 at addr ffff8801b22cf960 by task syzkaller256277/4521

CPU: 1 PID: 4521 Comm: syzkaller256277 Not tainted 4.16.0+ #15
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_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0xac/0x2f5 mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 tick_sched_handle+0x16d/0x180 kernel/time/tick-sched.c:171
 tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1179
 __run_hrtimer kernel/time/hrtimer.c:1337 [inline]
 __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1399
 hrtimer_interrupt+0x286/0x650 kernel/time/hrtimer.c:1457
 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
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:862
 </IRQ>
RIP: 0010:crypto_ctr_crypt_inplace crypto/ctr.c:123 [inline]
RIP: 0010:crypto_ctr_crypt+0x587/0x900 crypto/ctr.c:142
RSP: 0018:ffff8801b22cf980 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffff8801d9a32600 RBX: 0000000000000010 RCX: ffffffff830a3756
RDX: 0000000000000000 RSI: ffffffff830a3760 RDI: 0000000000000004
RBP: ffff8801b22cfb10 R08: ffff8801d9a32600 R09: 0000000000000000
R10: 0000000000000007 R11: 00000000095f721d R12: ffff8801d7db4650
R13: ffff8801b22cf940 R14: dffffc0000000000 R15: 0000000000000000
 skcipher_crypt_blkcipher crypto/skcipher.c:623 [inline]
 skcipher_encrypt_blkcipher+0x215/0x310 crypto/skcipher.c:632
 crypto_skcipher_encrypt include/crypto/skcipher.h:443 [inline]
 crypto_gcm_setkey+0x411/0x740 crypto/gcm.c:137
 crypto_aead_setkey+0xcb/0x220 crypto/aead.c:62
 aead_setkey+0x3c/0x50 crypto/algif_aead.c:526
 alg_setkey crypto/af_alg.c:223 [inline]
 alg_setsockopt+0x306/0x3b0 crypto/af_alg.c:256
 __sys_setsockopt+0x1bd/0x390 net/socket.c:1903
 SYSC_setsockopt net/socket.c:1914 [inline]
 SyS_setsockopt+0x34/0x50 net/socket.c:1911
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4461f9
RSP: 002b:00007f4bd4361ce8 EFLAGS: 00000206 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00000000006dbc5c RCX: 00000000004461f9
RDX: 0000000000000001 RSI: 0000000000000117 RDI: 00000000000003fd
RBP: 00000000006dbc58 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000204f7000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ffe1349a2af R14: 00007f4bd43629c0 R15: 0000000000000008

The buggy address belongs to the page:
page:ffffea0006c8b3c0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x2fffc0000000000()
raw: 02fffc0000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 ffffea0006c80101 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801b22cf800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b22cf880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801b22cf900: 00 00 00 00 ca ca ca ca 00 00 03 cb cb cb cb cb
                                                       ^
 ffff8801b22cf980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b22cfa00: f1 f1 f1 f1 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================