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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:344 [inline]
BUG: KASAN: slab-out-of-bounds in sha3_update+0xdf/0x2e0 crypto/sha3_generic.c:161
Write of size 244 at addr ffff8801cd9818fc by task syz-executor6/12261

CPU: 0 PID: 12261 Comm: syz-executor6 Not tainted 4.15.0-rc4-next-20171220+ #77
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:344 [inline]
 sha3_update+0xdf/0x2e0 crypto/sha3_generic.c:161
 crypto_shash_update+0xda/0x240 crypto/shash.c:110
 hmac_update+0x7e/0xa0 crypto/hmac.c:122
 crypto_shash_update+0xda/0x240 crypto/shash.c:110
 kdf_ctr security/keys/dh.c:181 [inline]
 keyctl_dh_compute_kdf security/keys/dh.c:226 [inline]
 __keyctl_dh_compute+0x160f/0x1990 security/keys/dh.c:398
 keyctl_dh_compute+0xac/0xf3 security/keys/dh.c:434
 SYSC_keyctl security/keys/keyctl.c:1741 [inline]
 SyS_keyctl+0x72/0x2c0 security/keys/keyctl.c:1637
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a09
RSP: 002b:00007f2157787c58 EFLAGS: 00000212 ORIG_RAX: 00000000000000fa
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452a09
RDX: 00000000206ec000 RSI: 00000000208f4000 RDI: 0000000000000017
RBP: 000000000000039b R08: 0000000020d21fc8 R09: 0000000000000000
R10: 0000000000000012 R11: 0000000000000212 R12: 00000000006f2728
R13: 00000000ffffffff R14: 00007f21577886d4 R15: 0000000000000000

Allocated by task 12261:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3709 [inline]
 __kmalloc+0x162/0x760 mm/slab.c:3718
 kmalloc include/linux/slab.h:521 [inline]
 kdf_alloc security/keys/dh.c:111 [inline]
 __keyctl_dh_compute+0x2b0/0x1990 security/keys/dh.c:288
 keyctl_dh_compute+0xac/0xf3 security/keys/dh.c:434
 SYSC_keyctl security/keys/keyctl.c:1741 [inline]
 SyS_keyctl+0x72/0x2c0 security/keys/keyctl.c:1637
 entry_SYSCALL_64_fastpath+0x1f/0x96

Freed by task 8212:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3489 [inline]
 kfree+0xd6/0x260 mm/slab.c:3804
 free_pipe_info+0x200/0x2a0 fs/pipe.c:679
 put_pipe_info+0xb0/0xd0 fs/pipe.c:561
 pipe_release+0x1af/0x250 fs/pipe.c:582
 __fput+0x327/0x7e0 fs/file_table.c:209
 ____fput+0x15/0x20 fs/file_table.c:243
 task_work_run+0x199/0x270 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x9bb/0x1ad0 kernel/exit.c:869
 do_group_exit+0x149/0x400 kernel/exit.c:972
 SYSC_exit_group kernel/exit.c:983 [inline]
 SyS_exit_group+0x1d/0x20 kernel/exit.c:981
 entry_SYSCALL_64_fastpath+0x1f/0x96

The buggy address belongs to the object at ffff8801cd981800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 252 bytes inside of
 512-byte region [ffff8801cd981800, ffff8801cd981a00)
The buggy address belongs to the page:
page:000000008ea890e1 count:1 mapcount:0 mapping:00000000b77d2716 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801cd981080 0000000000000000 0000000100000006
raw: ffffea000739de60 ffffea000735d060 ffff8801dac00940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801cd981880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801cd981900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801cd981980: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff8801cd981a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801cd981a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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