KASAN errors after 21c8e72037fb ("crypto: testmgr - use calculated count for number of test vectors")

[Laura Abbott]

Hi,

While attempting to debug something else, I saw KASAN errors
from the crypto test with ccm:

[   28.231615] ==================================================================
[   28.232007] BUG: KASAN: global-out-of-bounds in __test_aead+0x9d9/0x2200 at addr ffffffff8212fca0
[   28.232007] Read of size 16 by task cryptomgr_test/1107
[   28.232007] Address belongs to variable 0xffffffff8212fca0
[   28.232007] CPU: 0 PID: 1107 Comm: cryptomgr_test Not tainted 4.10.0+ #45
[   28.232007] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
[   28.232007] Call Trace:
[   28.232007]  dump_stack+0x63/0x8a
[   28.232007]  kasan_report.part.1+0x4a7/0x4e0
[   28.232007]  ? __test_aead+0x9d9/0x2200
[   28.232007]  ? crypto_ccm_init_crypt+0x218/0x3c0 [ccm]
[   28.232007]  kasan_report+0x20/0x30
[   28.232007]  check_memory_region+0x13c/0x1a0
[   28.232007]  memcpy+0x23/0x50
[   28.232007]  __test_aead+0x9d9/0x2200
[   28.232007]  ? kasan_unpoison_shadow+0x35/0x50
[   28.232007]  ? alg_test_akcipher+0xf0/0xf0
[   28.232007]  ? crypto_skcipher_init_tfm+0x2e3/0x310
[   28.232007]  ? crypto_spawn_tfm2+0x37/0x60
[   28.232007]  ? crypto_ccm_init_tfm+0xa9/0xd0 [ccm]
[   28.232007]  ? crypto_aead_init_tfm+0x7b/0x90
[   28.232007]  ? crypto_alloc_tfm+0xc4/0x190
[   28.232007]  test_aead+0x28/0xc0
[   28.232007]  alg_test_aead+0x54/0xd0
[   28.232007]  alg_test+0x1eb/0x3d0
[   28.232007]  ? alg_find_test+0x90/0x90
[   28.232007]  ? __sched_text_start+0x8/0x8
[   28.232007]  ? __wake_up_common+0x70/0xb0
[   28.232007]  cryptomgr_test+0x4d/0x60
[   28.232007]  kthread+0x173/0x1c0
[   28.232007]  ? crypto_acomp_scomp_free_ctx+0x60/0x60
[   28.232007]  ? kthread_create_on_node+0xa0/0xa0
[   28.232007]  ret_from_fork+0x2c/0x40
[   28.232007] Memory state around the buggy address:
[   28.232007]  ffffffff8212fb80: 00 00 00 00 01 fa fa fa fa fa fa fa 00 00 00 00
[   28.232007]  ffffffff8212fc00: 00 01 fa fa fa fa fa fa 00 00 00 00 01 fa fa fa
[   28.232007] >ffffffff8212fc80: fa fa fa fa 00 05 fa fa fa fa fa fa 00 00 00 00
[   28.232007]                                   ^
[   28.232007]  ffffffff8212fd00: 01 fa fa fa fa fa fa fa 00 00 00 00 01 fa fa fa
[   28.232007]  ffffffff8212fd80: fa fa fa fa 00 00 00 00 00 05 fa fa fa fa fa fa
[   28.232007] ==================================================================

This seems to be caused by 21c8e72037fb ("crypto: testmgr -
use calculated count for number of test vectors") but I think
it's because it  now exposes this test vector which always causes the failure.

{
                .key    = "\x7c\xc8\x18\x3b\x8d\x99\xe0\x7c"
                          "\x45\x41\xb8\xbd\x5c\xa7\xc2\x32"
                          "\x8a\xb8\x02\x59\xa4\xfe\xa9\x2c"
                          "\x09\x75\x9a\x9b\x3c\x9b\x27\x39",
                .klen   = 32,
                .iv     = "\x03\xf9\xd9\x4e\x63\xb5\x3d\x9d"
                          "\x43\xf6\x1e\x50",
                .assoc  = "\x57\xf5\x6b\x8b\x57\x5c\x3d\x3b"
                          "\x13\x02\x01\x0c\x83\x4c\x96\x35"
                          "\x8e\xd6\x39\xcf\x7d\x14\x9b\x94"
                          "\xb0\x39\x36\xe6\x8f\x57\xe0\x13",
                .alen   = 32,
                .input  = "\x3b\x6c\x29\x36\xb6\xef\x07\xa6"
                          "\x83\x72\x07\x4f\xcf\xfa\x66\x89"
                          "\x5f\xca\xb1\xba\xd5\x8f\x2c\x27"
                          "\x30\xdb\x75\x09\x93\xd4\x65\xe4",
                .ilen   = 32,
                .result = "\xb0\x88\x5a\x33\xaa\xe5\xc7\x1d"
                          "\x85\x23\xc7\xc6\x2f\xf4\x1e\x3d"
                          "\xcc\x63\x44\x25\x07\x78\x4f\x9e"
                          "\x96\xb8\x88\xeb\xbc\x48\x1f\x06"
                          "\x39\xaf\x39\xac\xd8\x4a\x80\x39"
                          "\x7b\x72\x8a\xf7",
                .rlen   = 44,
        },


If I pad iv with extra NULL bytes the KASAN error goes away.

Thoughts?

Thanks,
Laura