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 417B928B400; Mon, 5 May 2025 23:20:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746487230; cv=none; b=c/vFKP2VKQ6xRNfPZ8AQ7/lFejvWIzssVj84C6QGoCY0V7anHXe7fz1ECzNvWh2sEtM7OjNtdyC4LQMBe74wEEFS68tMsz/xBKWYu4AbIjqgQ2Md4LD+Fl0A0rpxSw+5V0j25wz5XbQ3ue+d3Evk90tXckCHOLCxTJgdcjzJYvE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746487230; c=relaxed/simple; bh=vqnvNS9eSoUsYXNZeDhxKTBqZfo8233lKjz1aoDaY1s=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=fadktpMguBGjoQ2Buf6VvFNph+CiReq96sdwJ2sy8Y4rA2kJpSLPfwo0TY4pSS97OFB0tosQrjtMPRhG8hsO0ZNKowvnZQBJ4PaHdc/kGUDKqldX3BF0ZKJan2BdIB7iSVr0HY7Y7/s/zIaoInw6A6ZnB8SW+orgoVBwACpTPdQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DCW1soBz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DCW1soBz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 277D4C4CEE4; Mon, 5 May 2025 23:20:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746487229; bh=vqnvNS9eSoUsYXNZeDhxKTBqZfo8233lKjz1aoDaY1s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DCW1soBzcLP2Y0fOS/MTVpkUL8Bea+/MJ7zam7gkINSe1okGIvB3JkxRrxaqShK2W gtUw12qtZc1zIIuCUyt+lBndPR6QeiMkQBr8zYhgv4PLNazHU74j75rXHEBIKi8duK 94aSXmGA9jmen+5FjkCqPez1aB3DMreUp3VUoY0YKpxV35SFHxKwbcQgJRAgU5p39Y vanfKK/MHQzHuacyQaF0KJVfaUeiCpLDmyaDepL/gJXTfzELwnG07nolWzcCHySaAN S3RS/7XLXPa13H1yE3519IfqKAaC544G8zdWafvYhoG17pUX99KevRfPmhi4ZRhLjC YGWOJt8oDLFCQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nandakumar Edamana , Andrii Nakryiko , Sasha Levin , eddyz87@gmail.com, ast@kernel.org, daniel@iogearbox.net, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 5.10 067/114] libbpf: Fix out-of-bound read Date: Mon, 5 May 2025 19:17:30 -0400 Message-Id: <20250505231817.2697367-67-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505231817.2697367-1-sashal@kernel.org> References: <20250505231817.2697367-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.10.237 Content-Transfer-Encoding: 8bit From: Nandakumar Edamana [ Upstream commit 236d3910117e9f97ebf75e511d8bcc950f1a4e5f ] In `set_kcfg_value_str`, an untrusted string is accessed with the assumption that it will be at least two characters long due to the presence of checks for opening and closing quotes. But the check for the closing quote (value[len - 1] != '"') misses the fact that it could be checking the opening quote itself in case of an invalid input that consists of just the opening quote. This commit adds an explicit check to make sure the string is at least two characters long. Signed-off-by: Nandakumar Edamana Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250221210110.3182084-1-nandakumar@nandakumar.co.in Signed-off-by: Sasha Levin --- tools/lib/bpf/libbpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 33cdcfe106344..f65e03e7cf944 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1503,7 +1503,7 @@ static int set_kcfg_value_str(struct extern_desc *ext, char *ext_val, } len = strlen(value); - if (value[len - 1] != '"') { + if (len < 2 || value[len - 1] != '"') { pr_warn("extern (kcfg) '%s': invalid string config '%s'\n", ext->name, value); return -EINVAL; -- 2.39.5