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 530093F23DD; Tue, 17 Mar 2026 17:01:01 +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=1773766861; cv=none; b=XKhfOlGR/JCJCguGY0+ERto+TTc1IhLa9gGD33d+GupNGCm/KI1cl/spsjSm2P89q6Gtm0wk8WI2zfwcn62m3Nr1SkQyB3EwS/cJuYfvnlMUlHVu7laY02UiLO4A0bFEsvmLGKaj64M4TsMrZRG5a6AmvWx11iBfvTSbMAtP+Cw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773766861; c=relaxed/simple; bh=UdZZUpQtNtdeLV383KGGzHd/qRjNhmWRxMSfIJt1dXU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GkTstPxnl2mfolUIC4C4QfN1vgHmEJDbRhgw7c+J/xdLb/koxU9QDSUbn1CyYGP0vtDOLEIqOtK6hmWCtGgZ6hwig2jB8arWNFIkHxZR0aNqPYal8QZSjuc5ndK75vsZCJYJ0iMYWFv5m/e6M4yHbj49oObd+lq2jNN4+hqSM7g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ViHI2zOE; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ViHI2zOE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3A5FC4CEF7; Tue, 17 Mar 2026 17:01:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1773766861; bh=UdZZUpQtNtdeLV383KGGzHd/qRjNhmWRxMSfIJt1dXU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ViHI2zOE3pgOeRU3nNdx057x09NZdV3J8o74ATmZ0dJd67wwpEq33ysIMJ38wu67G 5HEb3+Z6JmarUcbgqlYSOiWfn6ldy19hxNYJuDpMLMzklbLdJEMGT028doWVRCDGIL 8AAET0kuWfk1QcwF9D33fF/316MY7Lpx6WjWfOkE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Josh Law , "Masami Hiramatsu (Google)" Subject: [PATCH 6.19 336/378] lib/bootconfig: fix snprintf truncation check in xbc_node_compose_key_after() Date: Tue, 17 Mar 2026 17:34:53 +0100 Message-ID: <20260317163019.344329848@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260317163006.959177102@linuxfoundation.org> References: <20260317163006.959177102@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josh Law commit 1120a36bb1e9b9e22de75ecb4ef0b998f73a97f1 upstream. snprintf() returns the number of characters that would have been written excluding the NUL terminator. Output is truncated when the return value is >= the buffer size, not just > the buffer size. When ret == size, the current code takes the non-truncated path, advancing buf by ret and reducing size to 0. This is wrong because the output was actually truncated (the last character was replaced by NUL). Fix by using >= so the truncation path is taken correctly. Link: https://lore.kernel.org/all/20260312191143.28719-4-objecting@objecting.org/ Fixes: 76db5a27a827 ("bootconfig: Add Extra Boot Config support") Cc: stable@vger.kernel.org Signed-off-by: Josh Law Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Greg Kroah-Hartman --- lib/bootconfig.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/bootconfig.c +++ b/lib/bootconfig.c @@ -316,7 +316,7 @@ int __init xbc_node_compose_key_after(st depth ? "." : ""); if (ret < 0) return ret; - if (ret > size) { + if (ret >= size) { size = 0; } else { size -= ret;