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 C123236607D; Thu, 30 Jul 2026 15:47:30 +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=1785426451; cv=none; b=EAFvPj/l69SYBINfO5JX2jXUHUjm0ijswdvHyY/w445FSYqj0N1Lf3qefkuoRvcf//+UweqXLEspSqUH8Z/8gVsx2rN3dfC7m22L5/8x39rd+LrDGtc3kq2340FSx0A1Cs6udYVlNdy07DcBYAYzDB5+1/6/qYzPzB9iKCbRLsE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785426451; c=relaxed/simple; bh=mnDgaq1Z9B//rS1stFPMAxY1ZRzFbYpKJpAihYLpM98=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=G1e++ZZWFxJGDbEmEtvucXbPGDNbzSqHjN1hKCus8OAqlc7g+T+cBohW3Yy2hVP23UsgzLwiZ42Iz3jXJ2yWN4qxylJQpRAi+wj7e6Kg6FC//N0C3G7Uv3EmOPCTDl/wlKXWA8hi2eykvuQDGUoz48U/RGHnGaGeDWBgNQ05Iwo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bPnjuQYt; 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="bPnjuQYt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1980D1F000E9; Thu, 30 Jul 2026 15:47:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785426450; bh=YCopve5lxIufF5BkQFnfKYzV3yxc3DmcDY9PGxCuCFQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bPnjuQYtYhq+lTzZaaXs6NBBZ5Se4fJbT8usbKvEEJd8QldTeDOdhff4Uim8iJjKz 8pZ9SszxrYo8rYVdJBdbusnDKFbT1LeXCgAuDBdGMdIqyGX6XF/ggmbhDb5tSBaP0G 1Xtf31q4dzA5k+/cHDIDfY5CHIWMFM3uvMXoBkBU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Masami Hiramatsu (Google)" Subject: [PATCH 6.12 380/602] tracing/probes: Fix potential underflow in LEN_OR_ZERO macro Date: Thu, 30 Jul 2026 16:12:52 +0200 Message-ID: <20260730141443.943599737@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141435.976815864@linuxfoundation.org> References: <20260730141435.976815864@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu (Google) commit 8ce20bfba48902e1382187cd1a852f7cf3a1e739 upstream. In __set_print_fmt(), LEN_OR_ZERO is defined as (len ? len - pos : 0). If len is non-zero but smaller than pos, len - pos evaluates to a negative integer. When passed as a size argument to snprintf(), this negative value is cast to a large unsigned size_t, bypassing buffer size limits. Ensure len > pos before subtracting to avoid integer underflow. Link: https://lore.kernel.org/all/178454234934.290363.15247317871499514139.stgit@devnote2/ Fixes: 5bf652aaf46c ("tracing/probes: Integrate duplicate set_print_fmt()") Cc: stable@vger.kernel.org Assisted-by: Antigravity:gemini-3.5-flash Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_probe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -1886,7 +1886,7 @@ int traceprobe_update_arg(struct probe_a } /* When len=0, we just calculate the needed length */ -#define LEN_OR_ZERO (len ? len - pos : 0) +#define LEN_OR_ZERO (len > pos ? len - pos : 0) static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, enum probe_print_type ptype) {