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 E5BA52FF672; Mon, 8 Jun 2026 01:32:42 +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=1780882363; cv=none; b=gSvg2K7JcwXwc3M0KSRhe8odLQHpLq7y5MCH3RmVAhYDAnZEAdUKNycVs8DWKW1OCNAbMZNSk+g2PoIVqnPIP5e38WGzuhFYWT9Q25Da839oQHGY3F9bQrZEklThEpgT11mufbH6l+J4Y+KNXciUF8hEZd0G+p5qxQ1fLZd9wK0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780882363; c=relaxed/simple; bh=pztbD3iX3pd/KugXnN4XjAccZtUYB6eLIx5zr1pj1X4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aptjqoiZ1Ps/i5PqzHWcp4Hh9JpeVujv4uSXtlu46g3gW8ou1AhJUMGZrdwgWV83b+zJRM4vgAP55xOa5aTBLOajdgs4/1C0r6epFhrJ1U6S6gdGg3iWhpz3aUOO9Ik5C8cPxYcjOTnEHW1krR/Bp0QplysPlnHAVgw6b54cgT4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PanchjKr; 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="PanchjKr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 562CF1F00893; Mon, 8 Jun 2026 01:32:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780882362; bh=vJrjz18WP9YOQVzzuYUbzW7bbrjWzAs6Y8JS41ckrzw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=PanchjKrWbxEKsw3/+lBei8PMyInExfAPwQ0cLNJjXu68pB4k7+koAKTEYCOLMGOw 8+KYJTcaYkT5EyVoPkN9FwofmhmEA5uEj4Ucq0qzLuZVoar9IGLYCmivT9ey9XFAmn yn9IA2KjbezSBAmeQmJwPWL79/NSLd5sl5CaLWBvdRJpCyNOC8KZY+b5FuLIzGr+VR jMa6T5STjKpO/ct2A/rN4WpMQNnUWOCk81TjrGA2Bx69QSUFRBXTNwSHFuQJpMcD2y KSRF3vDHTM3N1F6Ke7IbPvFKBRb01jDAz/m7szD2WiME9Cy+CO+j4F5QJiohNBunKw sBAyeIlT9+CTw== From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Ingo Molnar , Thomas Gleixner , James Clark , Jiri Olsa , Ian Rogers , Adrian Hunter , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , sashiko-bot , "Claude Opus 4.6" Subject: [PATCH 11/11] perf tools: Use scnprintf() in build_id__snprintf() and hwmon read_events() Date: Sun, 7 Jun 2026 22:30:55 -0300 Message-ID: <20260608013057.1942953-12-acme@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260608013057.1942953-1-acme@kernel.org> References: <20260608013057.1942953-1-acme@kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Arnaldo Carvalho de Melo build_id__snprintf() and hwmon_pmu__read_events() accumulate formatted output via snprintf(), which returns the would-have-been-written count on truncation. In build_id__snprintf(), this inflates the return value beyond the buffer size. In hwmon_pmu__read_events(), len overshoots out_buf_len and the next 'out_buf_len - len' underflows. Switch both to scnprintf() which returns actual bytes written. Fixes: fccaaf6fbbc59910 ("perf build-id: Change sprintf functions to snprintf") Fixes: 53cc0b351ec99278 ("perf hwmon_pmu: Add a tool PMU exposing events from hwmon in sysfs") Reported-by: sashiko-bot Cc: Ian Rogers Assisted-by: Claude Opus 4.6 Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/build-id.c | 2 +- tools/perf/util/hwmon_pmu.c | 12 ++++++------ 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c index 8c0a9ae932aa5798..a3b92108f96263c6 100644 --- a/tools/perf/util/build-id.c +++ b/tools/perf/util/build-id.c @@ -94,7 +94,7 @@ int build_id__snprintf(const struct build_id *build_id, char *bf, size_t bf_size } for (size_t i = 0; i < build_id->size && offs < bf_size; ++i) - offs += snprintf(bf + offs, bf_size - offs, "%02x", build_id->data[i]); + offs += scnprintf(bf + offs, bf_size - offs, "%02x", build_id->data[i]); return offs; } diff --git a/tools/perf/util/hwmon_pmu.c b/tools/perf/util/hwmon_pmu.c index fb3ffa8d32ad2a93..dbf6a71af47f9a42 100644 --- a/tools/perf/util/hwmon_pmu.c +++ b/tools/perf/util/hwmon_pmu.c @@ -442,12 +442,12 @@ static size_t hwmon_pmu__describe_items(struct hwmon_pmu *hwm, char *out_buf, si buf[read_len] = '\0'; val = strtoll(buf, /*endptr=*/NULL, 10); - len += snprintf(out_buf + len, out_buf_len - len, "%s%s%s=%g%s", - len == 0 ? " " : ", ", - hwmon_item_strs[bit], - is_alarm ? "_alarm" : "", - (double)val / 1000.0, - hwmon_units[key.type]); + len += scnprintf(out_buf + len, out_buf_len - len, "%s%s%s=%g%s", + len == 0 ? " " : ", ", + hwmon_item_strs[bit], + is_alarm ? "_alarm" : "", + (double)val / 1000.0, + hwmon_units[key.type]); } close(fd); } -- 2.54.0