From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6CBE5749A for ; Thu, 12 Jan 2023 14:07:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D84C6C433EF; Thu, 12 Jan 2023 14:07:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673532442; bh=kLRMMStB7g+wf56rSA916CDdOHPvOd1kSflMlDPdbC0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WOSnQjNaP8Fng0c+MSTRt8Ffx88+8nC+1M6JeaQOMiLIMk32oi2yVsisxTCNHOpvF G+503qlFA5C6UdGR3C9kEbXW7yY2wm7rxjen3c9b68Bj/1wkl6Cw+YufCSiJVE4TfD upgmqubCnS4Fl7VxrKl6W+Zfj7eP5OyXnmRXJlmk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stanislav Fomichev , Martin KaFai Lau , Sasha Levin Subject: [PATCH 5.10 163/783] bpf: Move skb->len == 0 checks into __bpf_redirect Date: Thu, 12 Jan 2023 14:47:59 +0100 Message-Id: <20230112135531.886316383@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230112135524.143670746@linuxfoundation.org> References: <20230112135524.143670746@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Stanislav Fomichev [ Upstream commit 114039b342014680911c35bd6b72624180fd669a ] To avoid potentially breaking existing users. Both mac/no-mac cases have to be amended; mac_header >= network_header is not enough (verified with a new test, see next patch). Fixes: fd1894224407 ("bpf: Don't redirect packets with invalid pkt_len") Signed-off-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20221121180340.1983627-1-sdf@google.com Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin --- net/bpf/test_run.c | 3 --- net/core/filter.c | 7 ++++++- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 717b01ff9b2b..7df14a0e380c 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -442,9 +442,6 @@ static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb) { struct qdisc_skb_cb *cb = (struct qdisc_skb_cb *)skb->cb; - if (!skb->len) - return -EINVAL; - if (!__skb) return 0; diff --git a/net/core/filter.c b/net/core/filter.c index 4c22e6d1da74..ef7e74260afc 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2125,6 +2125,11 @@ static int __bpf_redirect_no_mac(struct sk_buff *skb, struct net_device *dev, { unsigned int mlen = skb_network_offset(skb); + if (unlikely(skb->len <= mlen)) { + kfree_skb(skb); + return -ERANGE; + } + if (mlen) { __skb_pull(skb, mlen); @@ -2146,7 +2151,7 @@ static int __bpf_redirect_common(struct sk_buff *skb, struct net_device *dev, u32 flags) { /* Verify that a link layer header is carried */ - if (unlikely(skb->mac_header >= skb->network_header)) { + if (unlikely(skb->mac_header >= skb->network_header || skb->len == 0)) { kfree_skb(skb); return -ERANGE; } -- 2.35.1