From nobody Wed Jun 17 07:29:35 2026 Received: from ha.d.sender-sib.com (ha.d.sender-sib.com [77.32.148.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B37B33A6EE3 for ; Thu, 23 Apr 2026 17:16:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=77.32.148.27 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776964607; cv=none; b=HMbYAEwQ6MsnC7GqNBkskOmmuCiLIFZbKjHRVtMr/gprrid8/30deafdQewMBn4WgdEeVcuSYiyDCy9RlonYnrHolGP3i9MjQQ4omMnjMZ5nGjzp1ifNuHDlO3S4klUm7F46xHD+aFxTojZxwZcNW+ElCFebFjCFwTQOr/eQPJE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776964607; c=relaxed/simple; bh=pvyYirCSrkeM14cOovyt45wUxDqhLZpCtG6pmoVTDY8=; h=Date:Cc:Message-Id:To:Subject:From:Mime-Version; b=GGCnG93WUlxqwAsNWRvYq3CYiOvmgViVqZKy41K9Na0lAusof+vEqNt75nR1tr3JT+LzBpmyRgC1HxGWEW1RzcVN76JQcWsjeE2k5FYKw9b+KykDf+VtiUK/4IWALhj2DHIR0/bWPiJ9uVw5ZkMtpxUx0Ey8om0Rtw9P8vgYGxE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=unknownbbqr.xyz; spf=pass smtp.mailfrom=ha.d.sender-sib.com; dkim=pass (2048-bit key) header.d=unknownbbqr.xyz header.i=@unknownbbqr.xyz header.b=G6qKSuNX; arc=none smtp.client-ip=77.32.148.27 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=unknownbbqr.xyz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ha.d.sender-sib.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=unknownbbqr.xyz header.i=@unknownbbqr.xyz header.b="G6qKSuNX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=unknownbbqr.xyz; q=dns/txt; s=brevo1; bh=kfcuniS6RT21aqFvwTrT2zicvEoH/Fexf2RcvUJZJlY=; h=from:subject:date:to:cc:mime-version:content-transfer-encoding:list-unsubscribe:x-csa-complaints:list-unsubscribe-post:message-id:x-sib-id:feedback-id; b=G6qKSuNXUeqw+mDCQXWFhCuqbn7fUmXGFVxqTHv5AAzIFzCLMpTb3bhfJFV/OyBpGaf9N/DzHo+u SJNg6w3QFHK+IzUslatBlHNHvPaVTNsCUBjPDOTxD3d9uowl1b1/HfEZxm2QpQGd/CGQGoU1YxzK 77yK+nAHt69/PA3C0d6v6Mavg8B6UGrFO9f6BJdvPgGDXmhWUUwZuFmwqERAA8SbheonvwSHSe12 M1Fu9B0dZ+uExd0mhJuaUlxWcJu5I6/8qgcHfVsP9T7C0bV4FJ/l3n5tZKS08dYOvVvzgl0jUf7Q ysvP7Z9XVza/imErYK7inQXQMgYRiYMQAQ0ZLQ== X-CSA-Complaints: csa-complaints@eco.de X-Mailin-EID: NDQzNzMzMzgyfmxpbnV4LWtlcm5lbEB2Z2VyLmtlcm5lbC5vcmd%2BPDIwMjYwNDIzMTcxNjM1LjQzNTUtMS1kZXZAdW5rbm93bmJicXIueHl6Pn5oYS5kLnNlbmRlci1zaWIuY29t Date: Thu, 23 Apr 2026 20:16:35 +0300 Cc: , , "unknownbbqrx" Message-Id: Origin-messageId: <20260423171635.4355-1-dev@unknownbbqr.xyz> Feedback-ID: 77.32.148.27:10473219_-1:10473219:Sendinblue To: Subject: [PATCH] tools/power/x86/intel-speed-select: harden daemon pidfile open X-sib-id: LJrLhwJPczDoFosQ9PO5xruAIXRHKiHsJvE3TqD110iyxG5_VI_lJ1OH0yo6ZSokNsE1DA1szRtqdE5fkRY9h-hpUCbS4pye430jwRMGrKWfhpxN3qIeG0VlETS9iluI3fywcYx_Sfo7PBL3pAKOdswHno-TdE1bRcn1q9dY_g2hNSeIM_td0v7Lzw List-Unsubscribe-Post: List-Unsubscribe=One-Click From: "unknownbbqrx" X-Mailer: git-send-email 2.53.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Avoid symlink-based pidfile clobbering by opening the pidfile with O_NOFOLL= OW and validating it with fstat() before locking/writing. The daemon currently uses a fixed pidfile path under /tmp. A local unprivil= eged user can pre-create a symlink at that path and cause a root-run daemon= instance to write into an attacker-chosen file. Signed-off-by: unknownbbqrx --- tools/power/x86/intel-speed-select/isst-daemon.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/tools/power/x86/intel-speed-select/isst-daemon.c b/tools/power= /x86/intel-speed-select/isst-daemon.c index 66df21b2b..4346b049d 100644 --- a/tools/power/x86/intel-speed-select/isst-daemon.c +++ b/tools/power/x86/intel-speed-select/isst-daemon.c @@ -200,11 +200,21 @@ static void daemonize(char *rundir, char *pidfile) if (ret =3D=3D -1) exit(EXIT_FAILURE); =20 - pid_file_handle =3D open(pidfile, O_RDWR | O_CREAT, 0600); + pid_file_handle =3D open(pidfile, O_RDWR | O_CREAT | O_NOFOLLOW, 0600); if (pid_file_handle =3D=3D -1) { /* Couldn't open lock file */ exit(1); } + + { + struct stat st; + + if (fstat(pid_file_handle, &st) =3D=3D -1) + exit(1); + + if (!S_ISREG(st.st_mode)) + exit(1); + } /* Try to lock file */ #ifdef LOCKF_SUPPORT if (lockf(pid_file_handle, F_TLOCK, 0) =3D=3D -1) { base-commit: 2e68039281932e6dc37718a1ea7cbb8e2cda42e6 prerequisite-patch-id: b61dd51dee390277603975bf729a687113185c3a prerequisite-patch-id: df28525061dd528875c7c75880b4684d80f4aa7d --=20 2.53.0