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 EEBFA392831; Thu, 30 Jul 2026 15:18:54 +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=1785424736; cv=none; b=AkL4Nk3Q5HViSHZ/OfUjsYFzGNdewQH4ihVGTSqa52tQ31YYBiVYg+Z7poYxjdhrU4n6sHBwv/BWFsDozT63Z0Gw4iBuE98QWgixVqq2zZ5eo7PxEwwrZ158KN7WK8W2bzDKCawhNZJzeMmQ6ZxURoNp+A1xc6QalMvuCjoub4c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785424736; c=relaxed/simple; bh=QSi50wikQLpiVzGfkdB3508DVryX2D0BGkTQQUuqcek=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OJn6CznreUjggvTAELr++qW6NLY4W7dpRLwA+BbbpJHZVqUVdbcsMPjodYd9+zK60yv0KbR4IWctG9JGt1vnBmKUAMt0TgI9UYVAjiEk+83N/e2a+dYi6wqQVUnAP3ZJXElWaokHELxnadJ+hqjZat3F2uWTmTHM29bntwIh0f8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WcEOEMWT; 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="WcEOEMWT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 512FF1F00A3F; Thu, 30 Jul 2026 15:18:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785424734; bh=iuFjjHv19B0Fz1oNtVAtf8KEv46FRV/+h5MD5g20Qxc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=WcEOEMWTixHJSiGazK0SVJNutxjXDqvCqxP4onDseR9SY9I9VXCDtz6OwrvMove58 CrXoFyCEZ3CG6EeGuoIcQqViW32onF/Zy4uO3N45SiMp5I89PuUJj3/jA73h+bG+Vp FqOCXHoWlxRvfR4DKGy44rkPzAqrhYgwNmhzArtI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Masami Hiramatsu (Google)" Subject: [PATCH 6.18 496/675] tracing/probes: Fix potential underflow in LEN_OR_ZERO macro Date: Thu, 30 Jul 2026 16:13:46 +0200 Message-ID: <20260730141455.667452196@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141445.110192266@linuxfoundation.org> References: <20260730141445.110192266@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 6.18-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 @@ -2018,7 +2018,7 @@ 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) {