Hello,

syzkaller hit the following crash on  
1ea8d039f9edcfefb20d8ddfe136930f6e551529
git://git.cmpxchg.org/linux-mmots.git/master
compiler: gcc (GCC) 7.1.1 20170620
.config is attached
Raw console output is attached.
C reproducer is attached
syzkaller reproducer is attached. See https://goo.gl/kgGztJ
for information about syzkaller reproducers


==================================================================
BUG: KASAN: stack-out-of-bounds in memcpy include/linux/string.h:341  
[inline]
BUG: KASAN: stack-out-of-bounds in sha3_update+0xdf/0x2e0  
crypto/sha3_generic.c:161
Write of size 4096 at addr ffff8801cca07c40 by task syzkaller076574/3044

CPU: 1 PID: 3044 Comm: syzkaller076574 Not tainted 4.14.0-mm1+ #25
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x257 lib/dump_stack.c:53
  print_address_description+0x73/0x250 mm/kasan/report.c:252
  kasan_report_error mm/kasan/report.c:351 [inline]
  kasan_report+0x25b/0x340 mm/kasan/report.c:409
  check_memory_region_inline mm/kasan/kasan.c:260 [inline]
  check_memory_region+0x137/0x190 mm/kasan/kasan.c:267
  memcpy+0x37/0x50 mm/kasan/kasan.c:303
  memcpy include/linux/string.h:341 [inline]
  sha3_update+0xdf/0x2e0 crypto/sha3_generic.c:161
  crypto_shash_update+0xcb/0x220 crypto/shash.c:109
  shash_finup_unaligned+0x2a/0x60 crypto/shash.c:151
  crypto_shash_finup+0xc4/0x120 crypto/shash.c:165
  hmac_finup+0x182/0x330 crypto/hmac.c:152
  crypto_shash_finup+0xc4/0x120 crypto/shash.c:165
  shash_digest_unaligned+0x9e/0xd0 crypto/shash.c:172
  crypto_shash_digest+0xc4/0x120 crypto/shash.c:186
  hmac_setkey+0x36a/0x690 crypto/hmac.c:66
  crypto_shash_setkey+0xad/0x190 crypto/shash.c:64
  shash_async_setkey+0x47/0x60 crypto/shash.c:207
  crypto_ahash_setkey+0xaf/0x180 crypto/ahash.c:200
  hash_setkey+0x40/0x90 crypto/algif_hash.c:446
  alg_setkey crypto/af_alg.c:221 [inline]
  alg_setsockopt+0x2a1/0x350 crypto/af_alg.c:254
  SYSC_setsockopt net/socket.c:1851 [inline]
  SyS_setsockopt+0x189/0x360 net/socket.c:1830
  entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x43fdb9
RSP: 002b:00007ffd5be32ba8 EFLAGS: 00000217 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fdb9
RDX: 0000000000000001 RSI: 0000000000000117 RDI: 0000000000000003
RBP: 0000000000000086 R08: 0000000000001000 R09: 0000000000000000
R10: 0000000020ea5000 R11: 0000000000000217 R12: 0000000000401720
R13: 00000000004017b0 R14: 0000000000000000 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea00073281c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x2fffc0000000000()
raw: 02fffc0000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 0000000100000001 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8801cca07d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ffff8801cca07e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ffff8801cca07e80: f1 f1 f1 f1 04 f2 f2 f2 f2 f2 f2 f2 04 f2 f2 f2
                    ^
  ffff8801cca07f00: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
  ffff8801cca07f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
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