Received-SPF: pass (google.com: domain of linux-crypto-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Stephan =?ISO-8859-1?Q?M=FCller?= <smueller@chronox.de>
To:     davem@davemloft.net, herbert@gondor.apana.org.au,
        linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
        syzkaller-bugs@googlegroups.com,
        syzbot <syzbot+2e635807decef724a1fa@syzkaller.appspotmail.com>
Subject: [PATCH] crypto: DRBG - always try to free Jitter RNG instance
Date:   Wed, 03 Jun 2020 10:08:56 +0200
Message-ID: <2583872.mvXUDI8C0e@positron.chronox.de>
In-Reply-To: <0000000000002a280b05a725cd93@google.com>
References: <0000000000002a280b05a725cd93@google.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 7Bit
Content-Type: text/plain; charset="us-ascii"
Sender: linux-crypto-owner@vger.kernel.org
Precedence: bulk

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 | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/crypto/drbg.c b/crypto/drbg.c
index 37526eb8c5d5..33d28016da2d 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1631,6 +1631,9 @@ 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);
+	}
+
+	if (drbg->jent) {
 		crypto_free_rng(drbg->jent);
 		drbg->jent = NULL;
 	}
-- 
2.26.2