crypto: drbg - set freed buffers to NULL

During freeing of the internal buffers used by the DRBG, set the pointer
to NULL. It is possible that the context with the freed buffers is
reused. In case of an error during initialization where the pointers
do not yet point to allocated memory, the NULL value prevents a double
free.

Cc: stable@vger.kernel.org
Fixes: 3cfc3b9721 ("crypto: drbg - use aligned buffers")
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Reported-by: syzbot+75397ee3df5c70164154@syzkaller.appspotmail.com
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Stephan Mueller 2018-04-12 08:40:55 +02:00 committed by Herbert Xu
parent b346e492d7
commit eea0d3ea75
1 changed files with 2 additions and 0 deletions

View File

@ -1134,8 +1134,10 @@ static inline void drbg_dealloc_state(struct drbg_state *drbg)
if (!drbg)
return;
kzfree(drbg->Vbuf);
drbg->Vbuf = NULL;
drbg->V = NULL;
kzfree(drbg->Cbuf);
drbg->Cbuf = NULL;
drbg->C = NULL;
kzfree(drbg->scratchpadbuf);
drbg->scratchpadbuf = NULL;