torture_rand segfaults with mbedtls

[Andreas Schneider <asn@xxxxxxxxxxxxxx>]

Hi Juraj,

torture_rand segfaults with mbedtls. Could you please investigate?

Thanks!

Backtrace:

(gdb) bt
#0  0x00007ffff706b33a in mbedtls_aesni_crypt_ecb (ctx=ctx@entry=0x68e068 
<ssh_mbedtls_ctr_drbg+40>, mode=mode@entry=1, 
    input=input@entry=0x68e040 <ssh_mbedtls_ctr_drbg> "", 
output=output@entry=0x7ffff4fd9b20 "") at /usr/src/debug/
mbedtls-2.6.0-1.fc27.x86_64/library/aesni.c:100
#1  0x00007ffff706a6ca in mbedtls_aes_crypt_ecb (ctx=ctx@entry=0x68e068 
<ssh_mbedtls_ctr_drbg+40>, mode=mode@entry=1, 
    input=input@entry=0x68e040 <ssh_mbedtls_ctr_drbg> "", 
output=output@entry=0x7ffff4fd9b20 "") at /usr/src/debug/
mbedtls-2.6.0-1.fc27.x86_64/library/aes.c:851
#2  0x00007ffff7075b7f in mbedtls_ctr_drbg_random_with_add (p_rng=0x68e040 
<ssh_mbedtls_ctr_drbg>, output=<optimized out>, output_len=1, 
additional=<optimized out>, 
    add_len=<optimized out>) at /usr/src/debug/mbedtls-2.6.0-1.fc27.x86_64/
library/ctr_drbg.c:380
#3  0x0000000000439fe4 in ssh_mbedtls_random (where=0x7ffff4fd9c1e, len=1, 
strong=0) at /home/asn/workspace/projects/libssh/src/libmbedcrypto.c:1110
#4  0x0000000000417dfc in ssh_get_random (where=0x7ffff4fd9c1e, len=1, 
strong=0) at /home/asn/workspace/projects/libssh/src/dh.c:147
#5  0x000000000040ec79 in torture_rand_thread (threadid=0x0) at /home/asn/
workspace/projects/libssh/tests/unittests/torture_rand.c:44
#6  0x00007ffff62be61b in start_thread () from /lib64/libpthread.so.0
#7  0x00007ffff5feb91f in clone () from /lib64/libc.so.6