From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f68.google.com (mail-pj1-f68.google.com [209.85.216.68]) (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 50EDE3D7D72 for ; Tue, 21 Apr 2026 13:52:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.68 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776779543; cv=none; b=B1uvjYOSYppdSpWzJxGlSO7wDVg6ma6ZN+DwlE9Efsx4dpobfH+OV/oaSKtyt9W2z2GTHEXEFdVCClrvyPdcEvo5j6qca5LOV2+bcnlSCn9rAjWeQAGhkaBJPtjddv00vPRDd89KEg8WAK16KKaWhT5oxfoagIPDCve8WsIH344= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776779543; c=relaxed/simple; bh=ByiQT7lLgCQOwWqHPaWMeDVb0F2Vvw2jG7L7jztwnF0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=t23OB+7OVtLMLPfadL3KdWRASg4tnZ9PByNurp4N97As/bpR8xuP7EysrrPtmtJQRE44unbXn7+gLuLFmwgg/hXMYetkCn7NkE5LJIju6+vgNSpjPWm390xi5Y/slEyUollS3HlOroVK4utE0PAZjcjPlfcWv53rmesoC5paALo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=KTDLoYu7; arc=none smtp.client-ip=209.85.216.68 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="KTDLoYu7" Received: by mail-pj1-f68.google.com with SMTP id 98e67ed59e1d1-35f9ab079bdso2682349a91.2 for ; Tue, 21 Apr 2026 06:52:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1776779542; x=1777384342; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=NALUEA81yJGIvnC0xpXYI2BfHv9RgPJcvmMljayDHa8=; b=KTDLoYu7QC5lvXtYnXzdCY10UvkVbro5sbrcn4SWrhns3EKWH8vOOniAxsoIa7H2Kk CtOnjJ017phpBgizc79PtieBMBtH47GuVCslR5IKkjSSNWBykZBjWD1vhatk9AWqLyqh E1U8wuZmwttLZhAgvpRfL+g5zD6CmTLGx7i71/PRl+Le70RkD9a5RxNfqUQJEH8XG4tZ EARlMvqexAVakWvD501CCuWHkdxqUeMx5mvm4+O7nkL8bQRdkiXYWmfvJY/EpepfnFRw 8XGAMb83HhhL5z/CGmN76u9AGRoxnjNoM9gSRCQ6iwsJ58rhEvTYDmyGICPMbLiEz3G3 DSxA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776779542; x=1777384342; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=NALUEA81yJGIvnC0xpXYI2BfHv9RgPJcvmMljayDHa8=; b=sP8OgDuPCmB8jPeq2z7XpocalJHtpQ1nQ2EPA9a2xjnQ556114arAUz2Hb4oADbfJP bpvPFSgd9OlVdMu7SvJxhtKGsFY9413U/exPM1sOEUGHG9Jpc9ncyd6ma54ICpXuLpvu 8VvrA10a0haQ2gMUlLgQbTQvt9qioKW8wEQHhLxaNHxpFhOegBNOsAiedtwuciKEITpp CI/VJVP2uw2Mlugmig0E1eR32lPO3XQkcEJAl4LzR/MA8dZgPJtfp3h49sPCZ4USDJt9 eTy0t42VKgORTnV024JrBqbWolFQEuaRGsRurM/iwSJrinGqwEjMJF1XxLxT/FsRLndH uBRg== X-Forwarded-Encrypted: i=1; AFNElJ9kExzXUoEGEJVOZ4jtrzL0Qru8c5npSQSlDfMs/eORam/VLrxi1JrDHA7muFuj9IyDBKLUfKvGzWTy9zU=@vger.kernel.org X-Gm-Message-State: AOJu0YzPmcRQVzNsfVyQG9uF+lCzsIi+mCbp0D8YYi3oxP7s82sIx/yF 4is2X4ll+4VmouwiVUIUlzomfa2AK6mSt9rJgggAMwMwT7p6VVj4Z89i X-Gm-Gg: AeBDieu75MMUn/Si6N1uGOx2HmyUIYQFILb8FewE45X9tfSfEODb56VYlCareaOWlpd JHihv//P9RndSJSRqKbDLjSJE4llsc2f41Og9+Gp1dBRNCpGXE+Y7uiW8Xdur9keuN95uIHVCm4 YhkpmgbRYM+VgRZHFQDGlR9EOGz2QiB9VsJsCpTOovCc3BXovgNZi08qg4qgOs+8c2Wa9z/sI+e 7pwQUP9SQnwF+rCPJZpiWmEoFwoEjVAvxNURhvDPaYncBmBIx22jLCLASe2alI5nx2usNbEoZEU 1WUYvGlqVyA4SAVsKuh7r4jVtZNyLCu3UZjCKoh2mfy4BnBmeWOrhlXiRHEA088aP4Nu1IWhwCz P5UngO+6WzVWDjE7KOM6hWBwKMZGRfVOSgQpT5zHfdxES00N+ugzn2OZC5Z7H+H1FQhW4Lg33Hn MgEujSbyWMQv3NRpmIsO5whjQV2vNDSNp49JGRLBMWTU+P6RailhnJ X-Received: by 2002:a17:90a:fc45:b0:35f:be11:b3e0 with SMTP id 98e67ed59e1d1-361403cd032mr17630071a91.2.1776779541526; Tue, 21 Apr 2026 06:52:21 -0700 (PDT) Received: from LAPTOP-1HUHJV8R.localdomain ([222.205.46.89]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-36141975515sm13580859a91.15.2026.04.21.06.52.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Apr 2026 06:52:21 -0700 (PDT) From: l1za0.sec@gmail.com To: mcgrof@kernel.org, russ.weight@linux.dev, gregkh@linuxfoundation.org Cc: rafael@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] drivers: firmware_loader: fix race between sysfs fallback cleanup and device removal Date: Tue, 21 Apr 2026 21:49:57 +0800 Message-ID: <20260421135013.36322-1-l1za0.sec@gmail.com> X-Mailer: git-send-email 2.51.0 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: Haocheng Yu A WARNING in firmware_fallback_sysfs is reported by a modified Syzkaller-based kernel fuzzing tool that we developed. The cause of this issue is a possible race condition between firmware sysfs fallback cleanup and hot-plug or other device lifecycle paths. In this case, fw_load_sysfs_fallback() might run cleanup after the fallback device has already been removed, i.e., it would execute device_del(), then dpm_sysfs_remove(), and finally trigger a warning in sysfs_remove_group(). This problem can be avoided by adding device_is_registered() check before calling device_del(). Signed-off-by: Haocheng Yu --- drivers/base/firmware_loader/fallback.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c index bf68e3947814..a8d8c494f82d 100644 --- a/drivers/base/firmware_loader/fallback.c +++ b/drivers/base/firmware_loader/fallback.c @@ -116,8 +116,9 @@ static int fw_load_sysfs_fallback(struct fw_sysfs *fw_sysfs, long timeout) } else if (fw_priv->is_paged_buf && !fw_priv->data) retval = -ENOMEM; -out: - device_del(f_dev); +out: + if (device_is_registered(f_dev)) + device_del(f_dev); err_put_dev: put_device(f_dev); return retval; base-commit: ffc253263a1375a65fa6c9f62a893e9767fbebfa -- 2.51.0