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BUG: KASAN: alloca-out-of-bounds in tick_sched_handle+0x16d/0x180 kernel/time/tick-sched.c:162
Read of size 8 at addr ffff8801961d7530 by task syz-executor6/15577

CPU: 0 PID: 15577 Comm: syz-executor6 Not tainted 4.16.0+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b9/0x29f lib/dump_stack.c:53
 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:162
 tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1170
 __run_hrtimer kernel/time/hrtimer.c:1349 [inline]
 __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1411
 hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1469
 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:kasan_unpoison_shadow+0x0/0x50 mm/kasan/kasan.c:51
RSP: 0018:ffff8801961d7558 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff12
RAX: 0000000000040000 RBX: 0000000000000010 RCX: ffffc900078c5000
RDX: 000000000000820b RSI: 0000000000000070 RDI: ffff8801961d7500
RBP: ffff8801961d7560 R08: ffff8801d92f2140 R09: 00000000a2e0fe42
R10: 00000000a278fe42 R11: 0000000000000000 R12: ffff8801ace817b0
R13: ffff8801961d7520 R14: dffffc0000000000 R15: 0000000000000000
 crypto_ctr_crypt_inplace crypto/ctr.c:123 [inline]
 crypto_ctr_crypt+0x596/0x900 crypto/ctr.c:142
 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_encrypt+0x429/0x570 crypto/gcm.c:483
 crypto_aead_encrypt include/crypto/aead.h:335 [inline]
 _aead_recvmsg crypto/algif_aead.c:314 [inline]
 aead_recvmsg+0x1225/0x1ba0 crypto/algif_aead.c:334
 aead_recvmsg_nokey+0x69/0x90 crypto/algif_aead.c:452
 sock_recvmsg_nosec net/socket.c:802 [inline]
 sock_recvmsg+0xd0/0x110 net/socket.c:809
 ___sys_recvmsg+0x2b6/0x680 net/socket.c:2279
 __sys_recvmsg+0x112/0x260 net/socket.c:2328
 SYSC_recvmsg net/socket.c:2338 [inline]
 SyS_recvmsg+0x29/0x30 net/socket.c:2335
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4552d9
RSP: 002b:00007f9fe3848c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007f9fe38496d4 RCX: 00000000004552d9
RDX: 0000000000000000 RSI: 0000000020000480 RDI: 0000000000000014
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000495 R14: 00000000006f9e98 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea00065875c0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x2fffc0000000000()
raw: 02fffc0000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 ffffea0006580101 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801961d7400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801961d7480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801961d7500: ca ca ca ca 00 00 cb cb cb cb cb cb 00 00 00 00
                                     ^
 ffff8801961d7580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1
 ffff8801961d7600: f1 f1 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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