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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+0xd7/0x270 crypto/sha3_generic.c:161
Write of size 192 at addr ffff8801cb33ce3c by task syz-executor4/5751

CPU: 0 PID: 5751 Comm: syz-executor4 Not tainted 4.15.0-rc6-mm1+ #51
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+0x137/0x198 lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report+0x23b/0x360 mm/kasan/report.c:412
 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+0xd7/0x270 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+0x1056/0x1300 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+0x23/0x9a
RIP: 0033:0x452ac9
RSP: 002b:00007f61c8b14c58 EFLAGS: 00000212 ORIG_RAX: 00000000000000fa
RAX: ffffffffffffffda RBX: 00007f61c8b15700 RCX: 0000000000452ac9
RDX: 00000000205cd000 RSI: 0000000020dc0ff4 RDI: 0000000000000017
RBP: 0000000000000000 R08: 000000002011afc8 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000212 R12: 0000000000000000
R13: 0000000000a2f7ef R14: 00007f61c8b159c0 R15: 0000000000000000

Allocated by task 5751:
 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:552
 __do_kmalloc mm/slab.c:3705 [inline]
 __kmalloc+0x162/0x760 mm/slab.c:3714
 kmalloc include/linux/slab.h:520 [inline]
 kdf_alloc security/keys/dh.c:111 [inline]
 __keyctl_dh_compute+0x26e/0x1300 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+0x23/0x9a

Freed by task 3464:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527
 __cache_free mm/slab.c:3485 [inline]
 kfree+0xd9/0x260 mm/slab.c:3800
 security_get_user_sids+0xab0/0xe90 security/selinux/ss/services.c:2535
 sel_write_user+0x27b/0x460 security/selinux/selinuxfs.c:996
 selinux_transaction_write+0xd1/0x130 security/selinux/selinuxfs.c:735
 __vfs_write+0xef/0x740 fs/read_write.c:480
 vfs_write+0x189/0x510 fs/read_write.c:544
 SYSC_write fs/read_write.c:589 [inline]
 SyS_write+0xd4/0x1a0 fs/read_write.c:581
 entry_SYSCALL_64_fastpath+0x23/0x9a

The buggy address belongs to the object at ffff8801cb33cd40
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 252 bytes inside of
 512-byte region [ffff8801cb33cd40, ffff8801cb33cf40)
The buggy address belongs to the page:
page:ffffea00072ccf00 count:1 mapcount:0 mapping:ffff8801cb33c0c0 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801cb33c0c0 0000000000000000 0000000100000006
raw: ffffea00073ffc20 ffffea00072c9de0 ffff8801db000940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801cb33cd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801cb33ce00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801cb33ce80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
                                              ^
 ffff8801cb33cf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801cb33cf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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