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 C6BEB343889; Sat, 12 Sep 2026 10:35:30 +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=1789209331; cv=none; b=kMSZ1tgacvBo6nOk1PnbKckY9spI97QPJigaMxgiTvfIkfAbmQ8XJZrsR7HXef3jJmUD7ja5n6ake2gi6P5VdTdJQFZWkAU7JEikTfpo6rkpDAsh+DRtX1lEaum7LxV842IkdnHEddv8PQsUcOjgzxZwS7DK320PmpNcfaA/eh4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789209331; c=relaxed/simple; bh=jDxoLEInKzJEuzYmaJZszJfU/r6JdZ6BRa8OaQ3R0aU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hUKWqCtU1yfONMl7ga+lbG5SlVYOio7T2QN8kH3qO0KbWUx9L4Sfo2lo90UvilzVC/3CReUME3OPQ35MuRrcoWpamDRH4Q1yMATxT71cyw5YhUwqtwjYI8EBrgLZg6GQLq4GweklYC2XNRhYL016znlufhGVATlMUjp1SrOc43c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rRoEWMwR; 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="rRoEWMwR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 92BEA1F0089A; Sat, 12 Sep 2026 10:35:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789209330; bh=FvpZUzBdhhe153XCrd37kUMRACAyKnEOmng83suNaSE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=rRoEWMwRc9aT1iiv2Flp9VWdJSIzzVQzyoDSrUELAk5WtUFHQgrBJv5zRThAM6XTs 1SGeSiVg6dm7hBHBo3rbGkPb9I5w3HFGRU531cZlSRKLigYjFKIUih2oTzj1W1/tbF czNmXoYjtWRHwlBQ1JSyvx0bFzpr4f+6dKh2FPGo= 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 , Namhyung Kim , Sasha Levin Subject: [PATCH 6.18 0782/1518] perf machine: Check snprintf truncation in machines__findnew() Date: Sat, 12 Sep 2026 08:49:11 +0200 Message-ID: <20260912065641.127599640@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065623.398859879@linuxfoundation.org> References: <20260912065623.398859879@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: Arnaldo Carvalho de Melo [ Upstream commit cc6abe0012bf8c04af8275266f8ed7c55ba4a5fb ] The guestmount path is built with snprintf() into a PATH_MAX buffer without checking the return value. If symbol_conf.guestmount is long enough to cause truncation, the truncated path could match a different directory, causing the wrong guest to be associated with the pid. Check for truncation and bail out early. Fixes: a1645ce12adb ("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: Namhyung Kim Signed-off-by: Sasha Levin --- tools/perf/util/machine.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 25591f9969e15..8455cd94756e1 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -327,7 +327,12 @@ struct machine *machines__findnew(struct machines *machines, pid_t pid) if ((pid != HOST_KERNEL_ID) && (pid != DEFAULT_GUEST_KERNEL_ID) && (symbol_conf.guestmount)) { - snprintf(path, sizeof(path), "%s/%d", symbol_conf.guestmount, pid); + if (snprintf(path, sizeof(path), "%s/%d", + symbol_conf.guestmount, pid) >= (int)sizeof(path)) { + pr_err("Guest path too long for pid %d\n", pid); + machine = NULL; + goto out; + } if (access(path, R_OK)) { static struct strlist *seen; -- 2.53.0