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authorTobias Brunner <tobias@strongswan.org>2021-09-28 19:38:22 +0200
committerDaniil Baturin <daniil@vyos.io>2021-11-24 10:17:53 -0500
commitcfdaa88a6a069d98d082fc464cd4b4aa7ff3105d (patch)
tree5fbd6bee4e0460bb5ec8b4071e732d0b3b1abdd2
parent2d899ce706ccb01dc9e8193aebca297058094391 (diff)
downloadvyos-strongswan-1.2.9-S1.tar.gz
vyos-strongswan-1.2.9-S1.zip
cert-cache: Prevent crash due to integer overflow/sign change1.2.9-S1crux
random() allocates values in the range [0, RAND_MAX], with RAND_MAX usually equaling INT_MAX = 2^31-1. Previously, values between 0 and 31 were added directly to that offset before applying`% CACHE_SIZE` to get an index into the cache array. If the random value was very high, this resulted in an integer overflow and a negative index value and, therefore, an out-of-bounds access of the array and in turn dereferencing invalid pointers when trying to acquire the read lock. This most likely results in a segmentation fault. Fixes: 764e8b2211ce ("reimplemented certificate cache") Fixes: CVE-2021-41991 Signed-off-by: Daniil Baturin <daniil@vyos.io>
-rw-r--r--src/libstrongswan/credentials/sets/cert_cache.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/src/libstrongswan/credentials/sets/cert_cache.c b/src/libstrongswan/credentials/sets/cert_cache.c
index f1579c60a..ceebb3843 100644
--- a/src/libstrongswan/credentials/sets/cert_cache.c
+++ b/src/libstrongswan/credentials/sets/cert_cache.c
@@ -151,7 +151,7 @@ static void cache(private_cert_cache_t *this,
for (try = 0; try < REPLACE_TRIES; try++)
{
/* replace a random relation */
- offset = random();
+ offset = random() % CACHE_SIZE;
for (i = 0; i < CACHE_SIZE; i++)
{
rel = &this->relations[(i + offset) % CACHE_SIZE];