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 CBF963DEFE7; Mon, 20 Jul 2026 10:12:21 +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=1784542349; cv=none; b=X3N0CPRPZEjkDq16I9MdpEHafYveolXsHdZwFFn9rYp9dKTrARmqOIsrMLwOrK+wmu2miKG1j9ebNKwq7xliUpW+ySsN0Ha7PkTYjD+CPSMuWwJDjNMY0QYGCT1jVFFZRiwUXrqVFLoHIb5z7d08GXE5O6KNO9xlZUMpAJjWr3M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784542349; c=relaxed/simple; bh=nW1XWdnCO2/couf4O46tAqF5rrEEQ3N4ykGS5f5lubw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=mctbGpep1VW4Y5SDMRBU2lIPd/xgw3KiWkZkwSHijkTs41InyKTTfLjla0nsC1knQTSXM7zca+mr3OizsuXjy5+xTdanXnc6jLYuhWLv9rvE/oAnJDDbUki/Y1LWTeffjClDE6EJUAjOM4pdbMVtTWARcdVVEA6NkUqFp9RPQGQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WDP8MkhQ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WDP8MkhQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E53601F00A3A; Mon, 20 Jul 2026 10:12:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784542334; bh=YxV8jmxvGTn0ml/JttIpiyp/M5Pb/0W7C9FqCS1HgJg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=WDP8MkhQagpBIZQK7vUKYt5uebHK+jlhFR7ZQHGbats8m3XbS7Igc97RJ82L3Qcc2 I7LSt2uj27nBRJD0KYO7RIeHdp8CKMg2HkUYW5WGkmoOfjl+VIsiTgRkzIIrUq69p8 0CjB6H9gCAG7WM5oSwa0sc55wubpkE7LqraAg00L+QdaQVa6u2tpW6ly/UwmyzAze6 HZ/Ik583+Xb2gTiFdtBqWCVX9DnJsK6I0Hmyr5pvtq/tTliH88+SXVj/hyuH8ORHED 6jEZvgZ2GJJFIaopEyxS+WBsvpIwf8Tvp9/EJvdYStD72wqPUpprfq5OgHHqkhrH9q Mik56rLRj8LTQ== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH 1/4] tracing/probes: Avoid temporary buffer truncation in trace_probe_match_command_args() Date: Mon, 20 Jul 2026 19:12:10 +0900 Message-ID: <178454233010.290363.10428767141343428804.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <178454232006.290363.11301475407231432622.stgit@devnote2> References: <178454232006.290363.11301475407231432622.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit From: Masami Hiramatsu (Google) In trace_probe_match_command_args(), a stack buffer buf[MAX_ARGSTR_LEN + 1] (256 bytes) is used to format "=". However, since name can be up to 32 bytes (MAX_ARG_NAME_LEN) and comm up to 255 bytes (MAX_ARGSTR_LEN), the formatted string can exceed 256 bytes and get truncated by snprintf(), causing spurious argument matching failures. Instead of formatting into a temporary buffer on stack, compare the argument name, the '=' delimiter, and the comm expression directly. Fixes: eb5bf81330a7 ("tracing/kprobe: Add per-probe delete from event") Cc: stable@vger.kernel.org Assisted-by: Antigravity:gemini-3.5-flash Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_probe.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index d17cfee77d9c..95e3d072321f 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -2338,16 +2338,17 @@ int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b) bool trace_probe_match_command_args(struct trace_probe *tp, int argc, const char **argv) { - char buf[MAX_ARGSTR_LEN + 1]; int i; if (tp->nr_args < argc) return false; for (i = 0; i < argc; i++) { - snprintf(buf, sizeof(buf), "%s=%s", - tp->args[i].name, tp->args[i].comm); - if (strcmp(buf, argv[i])) + int len = strlen(tp->args[i].name); + + if (strncmp(argv[i], tp->args[i].name, len) || + argv[i][len] != '=' || + strcmp(argv[i] + len + 1, tp->args[i].comm)) return false; } return true;