[PATCH v3] crypto: DRBG - always try to free Jitter RNG instance

Stephan Müller
2020-06-07T13:20:35Z

The Jitter RNG is unconditionally allocated as a seed source follwoing
the patch 97f2650e5040. Thus, the instance must always be deallocated.

Reported-by: syzbot+2e635807decef724a1fa@syzkaller.appspotmail.com
Fixes: 97f2650e5040 ("crypto: drbg - always seeded with SP800-90B ...")
Signed-off-by: Stephan Mueller <smueller@chronox.de>
---
crypto/drbg.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/crypto/drbg.c b/crypto/drbg.c
index 37526eb8c5d5..8d80d93cab97 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1631,10 +1631,12 @@ static int drbg_uninstantiate(struct drbg_state *drbg)
if (drbg->random_ready.func) {
del_random_ready_callback(&drbg->random_ready);
cancel_work_sync(&drbg->seed_work);
- crypto_free_rng(drbg->jent);
- drbg->jent = NULL;
}

+ if (!IS_ERR_OR_NULL(drbg->jent))
+ crypto_free_rng(drbg->jent);
+ drbg->jent = NULL;
+
if (drbg->d_ops)
drbg->d_ops->crypto_fini(drbg);
drbg_dealloc_state(drbg);
--
2.26.2