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 1677535C6B8; Tue, 21 Jul 2026 21:31:21 +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=1784669482; cv=none; b=hybfjYza7gmnjSGozo/tFONpJQ/CroX+wuRBxhy66K/TS6v6V2E/C7857xrwQkR/lpfizPyxkNUFReE9Fr3lwR9QZxaR+xiaHmiJ8q6+3eTVhylip3dMnaHeVj8V/K+fCsYtpyJg3dr+wGo29vYatLN99JfjVF0T9TVa7lWws1w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784669482; c=relaxed/simple; bh=wzQClRcYf+ym0gjGNasZST29TWuZA32+l/7YXBXp2u8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rOlR7kHcMc8DCt4RRe2VnONK5SMxAEJZgX/oO73y/gTdUeZiykPn2jVrLbeDQUE5ZfLit/c25xUzPORCcJ7dZhUrlu2wSy2vFsd7Fqm2ObR/y2X+ZFbm8ssCwhlhTdo6/WT8BoKQlgOxUgATQ9A8r4jMyeTG6M+gb95ZdQIYU7Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sWjkL1Dn; 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="sWjkL1Dn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B9DD1F00A3A; Tue, 21 Jul 2026 21:31:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784669481; bh=/8lKBssrdgGzqq7DjoEIhJuuqtWDeX3Mg6ys6MnrTjQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=sWjkL1DnLB80ViY5LdKVbw695LkxUXHnBZ0p/NAYex8dyqjDY4A6ONKQfYN1eBVAt +shCKuxgzlU6RaVppOLvjjPVC2t0R/C5DIRHkheeMAj6rSXt27gM19Y3k3t9J1+vJO Fq+rpIpBMHp6Ubruk71DLiMz/uaRMY2QYgKhOgyM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, sashiko-bot , "Zhang, Yanmin" , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH 6.1 0572/1067] perf machine: Use snprintf() for guestmount path construction Date: Tue, 21 Jul 2026 17:19:33 +0200 Message-ID: <20260721152437.401219936@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152424.521567757@linuxfoundation.org> References: <20260721152424.521567757@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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnaldo Carvalho de Melo [ Upstream commit fe63d3bca288c5bb983304efd5fc3a5ff3183403 ] machines__findnew() and machines__create_guest_kernel_maps() use sprintf() to build paths by prepending symbol_conf.guestmount. Both write into PATH_MAX stack buffers, but guestmount comes from user configuration and is not length-checked. A guestmount path at or near PATH_MAX causes a stack buffer overflow. Switch to snprintf() with sizeof() to prevent overflow. The subsequent access()/fopen() calls will fail on a truncated path. Fixes: a1645ce12adb6c9c ("perf: 'perf kvm' tool for monitoring guest performance from host") Reported-by: sashiko-bot Cc: Zhang, Yanmin Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/util/machine.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 419147da8d672b..41137c7b4cdacc 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -362,7 +362,7 @@ struct machine *machines__findnew(struct machines *machines, pid_t pid) if ((pid != HOST_KERNEL_ID) && (pid != DEFAULT_GUEST_KERNEL_ID) && (symbol_conf.guestmount)) { - sprintf(path, "%s/%d", symbol_conf.guestmount, pid); + snprintf(path, sizeof(path), "%s/%d", symbol_conf.guestmount, pid); if (access(path, R_OK)) { static struct strlist *seen; @@ -1365,9 +1365,9 @@ int machines__create_guest_kernel_maps(struct machines *machines) namelist[i]->d_name); continue; } - sprintf(path, "%s/%s/proc/kallsyms", - symbol_conf.guestmount, - namelist[i]->d_name); + snprintf(path, sizeof(path), "%s/%s/proc/kallsyms", + symbol_conf.guestmount, + namelist[i]->d_name); ret = access(path, R_OK); if (ret) { pr_debug("Can't access file %s\n", path); -- 2.53.0