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 DBD348820 for ; Fri, 10 Mar 2023 14:50:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60689C433A4; Fri, 10 Mar 2023 14:50:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678459808; bh=dA/mk0QwQ1mgdeZvN6qBOV9FEBjXhJeMIpYEhf4jX2c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d5JjyjuMDHSOeWauBEJ+uwJ9kI1uTFblDNtIDLqUjMJwke59fm4Q5l9V1LnLm91Fh GZBiRUcxdcR9kiczQZTN29Vp96CtMO1nlmOQU4lC0R/MmUXA1475uPeQXK42BxQYR3 xNzi0tUFUxDz+CZNQn4mBsr/R/0mKLtdddyxkAwI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ilya Leoshkevich , Andrii Nakryiko , Sasha Levin Subject: [PATCH 5.10 127/529] libbpf: Fix alen calculation in libbpf_nla_dump_errormsg() Date: Fri, 10 Mar 2023 14:34:30 +0100 Message-Id: <20230310133810.864440316@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230310133804.978589368@linuxfoundation.org> References: <20230310133804.978589368@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: Ilya Leoshkevich [ Upstream commit 17bcd27a08a21397698edf143084d7c87ce17946 ] The code assumes that everything that comes after nlmsgerr are nlattrs. When calculating their size, it does not account for the initial nlmsghdr. This may lead to accessing uninitialized memory. Fixes: bbf48c18ee0c ("libbpf: add error reporting in XDP") Signed-off-by: Ilya Leoshkevich Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20230210001210.395194-8-iii@linux.ibm.com Signed-off-by: Sasha Levin --- tools/lib/bpf/nlattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/lib/bpf/nlattr.c b/tools/lib/bpf/nlattr.c index b607fa9852b1c..1a04299a2a604 100644 --- a/tools/lib/bpf/nlattr.c +++ b/tools/lib/bpf/nlattr.c @@ -178,7 +178,7 @@ int libbpf_nla_dump_errormsg(struct nlmsghdr *nlh) hlen += nlmsg_len(&err->msg); attr = (struct nlattr *) ((void *) err + hlen); - alen = nlh->nlmsg_len - hlen; + alen = (void *)nlh + nlh->nlmsg_len - (void *)attr; if (libbpf_nla_parse(tb, NLMSGERR_ATTR_MAX, attr, alen, extack_policy) != 0) { -- 2.39.2