Message-ID: <0f144d68-37c8-1e4a-1516-a3a572f06f8f@redhat.com>
Date:   Thu, 11 Nov 2021 19:06:18 -0500
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Subject: Re: [PATCH] tipc: check for null after calling kmemdup
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To:     Tadeusz Struk <tadeusz.struk@linaro.org>
Cc:     Ying Xue <ying.xue@windriver.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, netdev@vger.kernel.org,
        tipc-discussion@lists.sourceforge.net,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Dmitry Vyukov <dvyukov@google.com>
References: <20211111205916.37899-1-tadeusz.struk@linaro.org>
From:   Jon Maloy <jmaloy@redhat.com>
In-Reply-To: <20211111205916.37899-1-tadeusz.struk@linaro.org>
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Precedence: bulk


On 11/11/21 15:59, Tadeusz Struk wrote:
> kmemdup can return a null pointer so need to check for it, otherwise
> the null key will be dereferenced later in tipc_crypto_key_xmit as
> can be seen in the trace [1].
>
> Cc: Jon Maloy <jmaloy@redhat.com>
> Cc: Ying Xue <ying.xue@windriver.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: netdev@vger.kernel.org
> Cc: tipc-discussion@lists.sourceforge.net
> Cc: linux-kernel@vger.kernel.org
> Cc: stable@vger.kernel.org # 5.15, 5.14, 5.10
>
> [1] https://syzkaller.appspot.com/bug?id=bca180abb29567b189efdbdb34cbf7ba851c2a58
>
> Reported-by: Dmitry Vyukov <dvyukov@google.com>
> Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org>
> ---
>   net/tipc/crypto.c | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c
> index dc60c32bb70d..988a343f9fd5 100644
> --- a/net/tipc/crypto.c
> +++ b/net/tipc/crypto.c
> @@ -597,6 +597,11 @@ static int tipc_aead_init(struct tipc_aead **aead, struct tipc_aead_key *ukey,
>   	tmp->cloned = NULL;
>   	tmp->authsize = TIPC_AES_GCM_TAG_SIZE;
>   	tmp->key = kmemdup(ukey, tipc_aead_key_size(ukey), GFP_KERNEL);
> +	if (!tmp->key) {
> +		free_percpu(tmp->tfm_entry);
> +		kfree_sensitive(tmp);
> +		return -ENOMEM;
> +	}
>   	memcpy(&tmp->salt, ukey->key + keylen, TIPC_AES_GCM_SALT_SIZE);
>   	atomic_set(&tmp->users, 0);
>   	atomic64_set(&tmp->seqno, 0);
Acked-by: Jon Maloy <jmaloy@redhat.com>