From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 28242503BD6 for ; Wed, 16 Sep 2026 14:18:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789568306; cv=none; b=MlC2fGvFf+8fBxxS6lHxh0lqiT4SItK4hNrQZ9jVvVQiEkft3gQo4w1UfA5DwXgoe6zGXb9JSz98VgOS7wrX3U4q/ea1yg8o3WGbtbFiNyAzvYiBEAzdrWmjMm2U46Sou1bt82ibGbmxbtYEOpJQdPshBVYsq2sFXSYwgrHmOac= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789568306; c=relaxed/simple; bh=++4dG7WaFnzUv9I42qjRbZ8o6366gH4rqmft9gV7vmI=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=c4fobnQ273G0mqWqAeC0qRlLStRlMMNULBgAMLAX3e5JQhXMqeQEG8XH61sQr1Syz52C8NN9Z/2ZO0a0GcjgNGZys3KkHO3yFhFPQq75H0MZEUwx2Mes+tKIEVC33aZq0oedT5Pxn8894/hdAXEwFpJYerltPXBskBTNOYIPwzw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=UmmAqovk; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="UmmAqovk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34B701F000FF; Wed, 16 Sep 2026 14:18:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789568303; bh=N/wE+e3j4JYuVf0+uF8p0q4AkA9D/TiBxNrTt8bfDk0=; h=Subject:To:Cc:From:Date; b=UmmAqovk0wFKfUX07OZPRHlkbrwafqzTLnAqxe4EUaM6Yee2ygHqhJwcg65fk5X/c m3uWjuOUbUonR/JgWsfnmSc181FyM2PHnlY1ED/CTG8fYiLkHy74KOGsldfhK0g56e mEe8wUkx76BvgafyJG2dz+zuEmokZac3c8th9zjE= Subject: FAILED: patch "[PATCH] tools/bootconfig: Fix integer overflow and truncation in size" failed to apply to 5.15-stable tree To: mhiramat@kernel.org,ekffu200098@gmail.com,sashiko-bot@kernel.org Cc: From: Date: Wed, 16 Sep 2026 15:16:16 +0100 Message-ID: <2026091616-brisket-appease-387d@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 462d0b066b613103f579793031429db2ca23abc0 # git commit -s git send-email --to '' --in-reply-to '2026091616-brisket-appease-387d@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 462d0b066b613103f579793031429db2ca23abc0 Mon Sep 17 00:00:00 2001 From: "Masami Hiramatsu (Google)" Date: Fri, 11 Sep 2026 00:15:24 +0900 Subject: [PATCH] tools/bootconfig: Fix integer overflow and truncation in size checks Sashiko reported that on 32-bit systems, if an attacker crafts size in the bootconfig footer such that adding BOOTCONFIG_FOOTER_SIZE wraps around (for instance, if size is 0xFFFFFFFF), the size check in load_xbc_from_initrd() can be bypassed: if (stat.st_size < size + BOOTCONFIG_FOOTER_SIZE) { pr_err("bootconfig size is too big\n"); return -E2BIG; } Furthermore, on 64-bit systems with an initrd > 4.29 GB, comparing a corrupted 32-bit size (e.g. 0xFFFFFFFF) against stat.st_size - BOOTCONFIG_FOOTER_SIZE can also bypass the check if size is not bounded. Similarly, load_xbc_file() passes 64-bit stat.st_size directly into the 32-bit int size parameter of load_xbc_fd(), truncating large standalone files (>= 2GB). In both cases, passing 0xFFFFFFFF to load_xbc_fd() truncates to -1, resulting in malloc(0), an integer overflow in read(), and an out-of-bounds null-byte write. Fix this by: 1. Rejecting size > XBC_DATA_MAX or size > stat.st_size - BOOTCONFIG_FOOTER_SIZE in load_xbc_from_initrd(). 2. Rejecting stat.st_size > XBC_DATA_MAX in load_xbc_file() before passing it to load_xbc_fd(). 3. Checking size < 0 || size > XBC_DATA_MAX defensively in load_xbc_fd(). Link: https://lore.kernel.org/all/178905332413.213925.3179977110281463499.stgit@devnote2/ Fixes: 950313ebf79c ("tools: bootconfig: Add bootconfig command") Cc: stable@vger.kernel.org Reported-by: Sashiko Closes: https://lore.kernel.org/all/20260909161113.16C691F00A3A@smtp.kernel.org/ Closes: https://lore.kernel.org/all/20260910010137.EE0431F000FF@smtp.kernel.org/ Assisted-by: Antigravity:gemini-3.8-flash Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Sang-Heon Jeon diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c index 7dc9fff9b637..17d971d47f87 100644 --- a/tools/bootconfig/main.c +++ b/tools/bootconfig/main.c @@ -140,6 +140,9 @@ static int load_xbc_fd(int fd, char **buf, int size) { int ret; + if (size < 0 || size > XBC_DATA_MAX) + return -EINVAL; + *buf = malloc(size + 1); if (!*buf) return -ENOMEM; @@ -168,6 +171,13 @@ static int load_xbc_file(const char *path, char **buf) return ret; } + if (stat.st_size > XBC_DATA_MAX) { + pr_err("%s size is too big\n", path); + ret = -E2BIG; + close(fd); + return ret; + } + ret = load_xbc_fd(fd, buf, stat.st_size); close(fd); @@ -218,7 +228,8 @@ static int load_xbc_from_initrd(int fd, char **buf) csum = le32toh(csum); /* Wrong size error */ - if (stat.st_size < size + BOOTCONFIG_FOOTER_SIZE) { + if (size > XBC_DATA_MAX || + size > stat.st_size - BOOTCONFIG_FOOTER_SIZE) { pr_err("bootconfig size is too big\n"); return -E2BIG; }