From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.smtp-ext.broadcom.com (lpdvsmtp12.broadcom.com [192.19.144.207]) (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 DC946327C09; Fri, 24 Jul 2026 21:41:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.19.144.207 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784929291; cv=none; b=Kr9IZH3KL0XbE5IKWxgm9Xz1FsWZX7OQDdSTqwHl4B4gtY6MpjmV+3Ww88vObJEEH5YOmflzFOtgq+LoA3O03a9Gvz+fjtFtc1cxLHgcQheZuJ6m4lBVR1jYgpIVBqx9WKSrO3DHQxTpr5lvNX6HD6VrKCATU8GUVfUUzEMgD3I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784929291; c=relaxed/simple; bh=X6hKdn2YSvvafi2mgHuWo3wbqEvQXzvfO9b69Ah5G9c=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=q73pmu3mZu5PISiLKFAlQhTD5rsyzadsDWeHzc6HoofHz5SeHiRmMjPNs2qr/AZsctF4GrttWch7J76ATRgbFhhqJobtldjDFgagk5JY3ur8a236e73tSjxM02F0KFIbIcbgxvHIPFWrJlJkk9SsvNYMGKFLqAF3ABta6naxc2w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=broadcom.com; spf=fail smtp.mailfrom=broadcom.com; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b=DxCwqt8v; arc=none smtp.client-ip=192.19.144.207 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=broadcom.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=broadcom.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="DxCwqt8v" Received: from mail-lvn-it-01.broadcom.com (mail-lvn-it-01.lvn.broadcom.net [10.36.132.253]) by relay.smtp-ext.broadcom.com (Postfix) with ESMTP id DE90DC0003EC; Fri, 24 Jul 2026 14:41:21 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 relay.smtp-ext.broadcom.com DE90DC0003EC DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=broadcom.com; s=dkimrelay; t=1784929281; bh=X6hKdn2YSvvafi2mgHuWo3wbqEvQXzvfO9b69Ah5G9c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DxCwqt8vSB7LG+I6lGoGHH4diBONgRG14vAGZqmLx/sDE2y/bzZpJZuJQXPl92jia btTEYJTDmKtEnmEfVE6FW6jI/EaMJA3o9YKu+yUrE2ydL4qO/9eYWzqPKImBoiuq2t +mtQSbMwsHkgxKnp4A+nP9nM/T/cwbRlc5Hbe+Ew= Received: from stbirv-lnx-1.igp.broadcom.net (stbirv-lnx-1.igp.broadcom.net [10.67.48.32]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail-lvn-it-01.broadcom.com (Postfix) with ESMTPSA id 7A579AD0; Fri, 24 Jul 2026 14:41:21 -0700 (PDT) From: Florian Fainelli To: stable@vger.kernel.org Cc: Benjamin Berg , Johannes Berg , Florian Fainelli , Richard Weinberger , Anton Ivanov , Johannes Berg , Brendan Higgins , David Gow , Rae Moar , Kees Cook , Jens Axboe , Al Viro , Tiwei Bie , linux-um@lists.infradead.org (open list:USER-MODE LINUX (UML)), linux-kernel@vger.kernel.org (open list), linux-kselftest@vger.kernel.org (open list:KERNEL UNIT TESTING FRAMEWORK (KUnit)), kunit-dev@googlegroups.com (open list:KERNEL UNIT TESTING FRAMEWORK (KUnit)), bcm-kernel-feedback-list@broadcom.com Subject: [PATCH stable 6.12 2/9] um: Set parent death signal for winch thread/process Date: Fri, 24 Jul 2026 14:41:12 -0700 Message-Id: <20260724214119.1066665-3-florian.fainelli@broadcom.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260724214119.1066665-1-florian.fainelli@broadcom.com> References: <20260724214119.1066665-1-florian.fainelli@broadcom.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Benjamin Berg commit fdb2ecd35d327a1fc6bba69b97f85b494e1f4b6b upstream The winch "thread" is really a separate process. Using prctl to set PR_SET_PDEATHSIG ensures that this separate thread will be killed if the UML kernel itself dies unexpectedly and does not perform proper cleanup. Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20240919124511.282088-5-benjamin@sipsolutions.net Signed-off-by: Johannes Berg Signed-off-by: Florian Fainelli --- arch/um/drivers/chan_user.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c index a66e556012c4..1434114b2f34 100644 --- a/arch/um/drivers/chan_user.c +++ b/arch/um/drivers/chan_user.c @@ -10,6 +10,7 @@ #include #include #include +#include #include "chan_user.h" #include #include @@ -161,6 +162,8 @@ static __noreturn int winch_thread(void *arg) int count; char c = 1; + prctl(PR_SET_PDEATHSIG, SIGKILL); + pty_fd = data->pty_fd; pipe_fd = data->pipe_fd; count = write(pipe_fd, &c, sizeof(c)); -- 2.34.1