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authorStephan Mueller <smueller@chronox.de>2018-04-12 08:40:55 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-05-01 12:58:23 -0700
commit674d38ea185006d46a4022920aed29525e137a7e (patch)
tree7feff0ad6715efcbda81b711a93236e5c71852e7 /crypto
parenta32a944a60c854ab44cf873dfc1954828f50b046 (diff)
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crypto: drbg - set freed buffers to NULL
commit eea0d3ea7546961f69f55b26714ac8fd71c7c020 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/drbg.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/crypto/drbg.c b/crypto/drbg.c
index 70018397e59a..6c3221313753 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;