From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 5CFE218DB35 for ; Sat, 14 Feb 2026 13:02:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771074179; cv=none; b=WGRjwPtkQ1aQnhqEewkvQU4xkmV5g0hw6o8lgWAw0Fg5KE7pfWBv1+MWpSiMDNs3wecjHiXxRxKdPgMdTkr0Z98zq60BFYKQ+CXFCwr+LMYKiK2HKpsCBii4afSOdwCotERrZJcjEBjkoGsAW1yNGoKKEvncbq80mJtuKJSnO8w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771074179; c=relaxed/simple; bh=YhiVJF9tVbyZAtcetqFH0FbmZS23K6OQBx5ipS4YLVk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=m93+tE+mVT+pwDDoQsdVmT2uYoZA35wt2du4JZSeYjXcWET9XOzdU/J2v3Rgxg/aKNDyB1LZ3gFgb721dGDNi52K+MzNITyL02/Eb8k9quc4eYVOzH1dj5Fom6gW5PtqekwJWPesUc3lrIWsCn43+ycyd/Q4EJYTnoQbuX/yU6I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qoV7iZjP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qoV7iZjP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6487EC16AAE; Sat, 14 Feb 2026 13:02:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771074179; bh=YhiVJF9tVbyZAtcetqFH0FbmZS23K6OQBx5ipS4YLVk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qoV7iZjP63E5o5+k1/lnUD+Wrl5H3jPaNbSXJCGCVhTw0aLvwzyCEHrNmr9cTx4Fl k25ChGaTKd4hT0FBc0d/PoS6BbKCrVut4HbDO+kQMefUjP0lylT1Tf1HZ5YXylhue+ qasObbd+MrzgszRNJhAsWfORFHcdojP562tyaWmFEBM8hsIDNrDAcau7WgDyGtKlrY F/2SCoJKvBIW5xBcaX75NfnDblxReEY8vgARNqgnCiFqlox9vFX8AormwT58L3QzCT QEzGS2/4QGX8Y+BlPUmAIMHe7LHdjelRccSIi76uHHzNNbk1Ar1Dqh2GPFMThSHFo7 Lk3SXTXobsHEw== From: Sasha Levin To: stable@vger.kernel.org Cc: Liu Song , Manivannan Sadhasivam , Bjorn Helgaas , stable@kernel.org, Sasha Levin Subject: [PATCH 5.15.y 3/3] PCI: endpoint: Avoid creating sub-groups asynchronously Date: Sat, 14 Feb 2026 08:02:54 -0500 Message-ID: <20260214130254.345213-3-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260214130254.345213-1-sashal@kernel.org> References: <2026021309-browse-cloud-99d5@gregkh> <20260214130254.345213-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Liu Song [ Upstream commit 7c5c7d06bd1f86d2c3ebe62be903a4ba42db4d2c ] The asynchronous creation of sub-groups by a delayed work could lead to a NULL pointer dereference when the driver directory is removed before the work completes. The crash can be easily reproduced with the following commands: # cd /sys/kernel/config/pci_ep/functions/pci_epf_test # for i in {1..20}; do mkdir test && rmdir test; done BUG: kernel NULL pointer dereference, address: 0000000000000088 ... Call Trace: configfs_register_group+0x3d/0x190 pci_epf_cfs_work+0x41/0x110 process_one_work+0x18f/0x350 worker_thread+0x25a/0x3a0 Fix this issue by using configfs_add_default_group() API which does not have the deadlock problem as configfs_register_group() and does not require the delayed work handler. Fixes: e85a2d783762 ("PCI: endpoint: Add support in configfs to associate two EPCs with EPF") Signed-off-by: Liu Song [mani: slightly reworded the description and added stable list] Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Cc: stable@kernel.org Link: https://patch.msgid.link/20250710143845409gLM6JdlwPhlHG9iX3F6jK@zte.com.cn Signed-off-by: Sasha Levin --- drivers/pci/endpoint/pci-ep-cfs.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c index eb3ae3abab242..3814050070491 100644 --- a/drivers/pci/endpoint/pci-ep-cfs.c +++ b/drivers/pci/endpoint/pci-ep-cfs.c @@ -23,7 +23,6 @@ struct pci_epf_group { struct config_group group; struct config_group primary_epc_group; struct config_group secondary_epc_group; - struct delayed_work cfs_work; struct pci_epf *epf; int index; }; @@ -100,7 +99,7 @@ static struct config_group secondary_epc_group = &epf_group->secondary_epc_group; config_group_init_type_name(secondary_epc_group, "secondary", &pci_secondary_epc_type); - configfs_register_group(&epf_group->group, secondary_epc_group); + configfs_add_default_group(secondary_epc_group, &epf_group->group); return secondary_epc_group; } @@ -160,7 +159,7 @@ static struct config_group config_group_init_type_name(primary_epc_group, "primary", &pci_primary_epc_type); - configfs_register_group(&epf_group->group, primary_epc_group); + configfs_add_default_group(primary_epc_group, &epf_group->group); return primary_epc_group; } @@ -534,15 +533,13 @@ static void pci_ep_cfs_add_type_group(struct pci_epf_group *epf_group) return; } - configfs_register_group(&epf_group->group, group); + configfs_add_default_group(group, &epf_group->group); } -static void pci_epf_cfs_work(struct work_struct *work) +static void pci_epf_cfs_add_sub_groups(struct pci_epf_group *epf_group) { - struct pci_epf_group *epf_group; struct config_group *group; - epf_group = container_of(work, struct pci_epf_group, cfs_work.work); group = pci_ep_cfs_add_primary_group(epf_group); if (IS_ERR(group)) { pr_err("failed to create 'primary' EPC interface\n"); @@ -601,9 +598,7 @@ static struct config_group *pci_epf_make(struct config_group *group, kfree(epf_name); - INIT_DELAYED_WORK(&epf_group->cfs_work, pci_epf_cfs_work); - queue_delayed_work(system_wq, &epf_group->cfs_work, - msecs_to_jiffies(1)); + pci_epf_cfs_add_sub_groups(epf_group); return &epf_group->group; -- 2.51.0