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 D8ED3361DA6; Wed, 10 Jun 2026 19:53:36 +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=1781121217; cv=none; b=UQwmw6ME9Y9Qc2M1KhiIQGQ9rHrghjV6Mk/7Gwr5MdtD3jp3s7pn6meR+81oMRr0XGkKsa97lGu9VukP2hpOmDT2oAldJxPks2/HHa6Ex6IhKxnZKCKZP5W7ZWCgEWHliobzHXqSR9jPn1ut1Fnq4eRp9anDMvgbsP2g1YNSSw8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781121217; c=relaxed/simple; bh=TXnI0tIKaOPTk7AUDAFrqpKB3FY8QjI0fF79NRZP8Yg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SDE5rVSJWyzmYBB5P96htUVoc9rqzyRZKcXhXS8OkCGL/tJNjYqc6H9EZ2MLTlRajnx0fOLLMvPeRtGoFX/7JPsGQs4Og48UYF1P996atOVbloxCsut/C4fkHuwF+sRseYljmBYtqShqDGiMz9Gl1U4WIWecEHGDYvw7BCmJzNc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AclH2Qmh; 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="AclH2Qmh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B60C61F00898; Wed, 10 Jun 2026 19:53:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781121216; bh=CbPCvN06o1gOnMzGEfRvn6eJx9i+NpYEoiN9TrKi3IM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=AclH2QmhZJl22GUUh+Fasaq8WgfWRk3f/WCWqQQuaRo8WBE4HFTLtfmVmML1/PD8Z +l63DQHLSi9AmiFGzGb1sdX7oXqnzW/Fmphev9GaqdEYeyeiLBNeAUkuRTwOCJ0bqh 0dVjv/s1N/1FBfKIaD+0MVBO/YKlIkvpgGfq+bZvAnvrK1cL241+1ktYQIZz2kaqET WUFN/N7YOH79xHZK12DHzAbHNQILCn+SDCfbilYQdP2sqFFf/c/pDtGmxyXVNrK2/p y5KtdlS/VnV78YCd4+AFSPdtlZT5XnBI740Dqm6JNMLjfPoU2NjTgDItOk7MJQB8Wo A7UvcMRFt1eQw== 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 18/23] tools lib api: Fix mount_overload() snprintf truncation and toupper range Date: Wed, 10 Jun 2026 16:51:51 -0300 Message-ID: <20260610195157.2091137-19-acme@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260610195157.2091137-1-acme@kernel.org> References: <20260610195157.2091137-1-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 mount_overload() builds an environment variable name like "PERF_SYSFS_ENVIRONMENT" from fs->name. Two bugs: 1) snprintf() uses name_len as the buffer size instead of sizeof(upper_name). For fs->name = "sysfs" (len=5), the output is truncated to "PERF" (4 chars + null), so getenv() never finds the intended variable. 2) mem_toupper() only uppercases name_len bytes, converting just the "PERF" prefix rather than the full string including the filesystem name portion. Fix by using sizeof(upper_name) for snprintf and strlen(upper_name) for mem_toupper, so the full "PERF_SYSFS_ENVIRONMENT" string is correctly formatted and uppercased. Reported-by: sashiko-bot Fixes: 73ca85ad364769ff ("tools lib api fs: Add FSTYPE__mount() method") Cc: Jiri Olsa Assisted-by: Claude Opus 4.6 Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/api/fs/fs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/lib/api/fs/fs.c b/tools/lib/api/fs/fs.c index d16911818d4d3569..cbd8eab0d1df0c6b 100644 --- a/tools/lib/api/fs/fs.c +++ b/tools/lib/api/fs/fs.c @@ -261,8 +261,8 @@ static const char *mount_overload(struct fs *fs) /* "PERF_" + name + "_ENVIRONMENT" + '\0' */ char upper_name[5 + name_len + 12 + 1]; - snprintf(upper_name, name_len, "PERF_%s_ENVIRONMENT", fs->name); - mem_toupper(upper_name, name_len); + snprintf(upper_name, sizeof(upper_name), "PERF_%s_ENVIRONMENT", fs->name); + mem_toupper(upper_name, strlen(upper_name)); return getenv(upper_name) ?: *fs->mounts; } -- 2.54.0