Commit eea0d3ea authored Apr 12, 2018 by Stephan Mueller Committed by Herbert Xu Apr 21, 2018

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: 3cfc3b97 ("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>

parent b346e492

crypto/drbg.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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;

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