From ef734472771a62ae9f901367a40a89382a991917 Mon Sep 17 00:00:00 2001 From: Stephan Mueller Date: Thu, 12 Apr 2018 08:40:55 +0200 Subject: 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: faba028f3f7b4 ("crypto: drbg - use aligned buffers") Signed-off-by: Stephan Mueller Reported-by: syzbot+75397ee3df5c70164154@syzkaller.appspotmail.com Signed-off-by: Herbert Xu --- crypto/drbg.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'crypto/drbg.c') diff --git a/crypto/drbg.c b/crypto/drbg.c index 4faa2781..466a112a 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -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; -- cgit v1.2.3