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authorStephan Mueller <smueller@chronox.de>2018-04-12 08:40:55 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2018-04-21 00:57:00 +0800
commiteea0d3ea7546961f69f55b26714ac8fd71c7c020 (patch)
tree1a8cda1a7a5932789790ff6286791d999307d7c9 /crypto/drbg.c
parentb346e492d7127e4332d5a9989b844b2095cc4fcd (diff)
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: 3cfc3b9721123 ("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>
Diffstat (limited to 'crypto/drbg.c')
-rw-r--r--crypto/drbg.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/crypto/drbg.c b/crypto/drbg.c
index 4faa2781c964..466a112a4446 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;