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 16877378D7C; Tue, 17 Feb 2026 20:45:03 +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=1771361103; cv=none; b=AxGiM+f9uRhouV1fLZOJGb+u7oEUp4bTTaMiBdEUZqV6hGY5oyjVcHh9034K+teEBQyP8PC+3+b6fCTwOKqEyYF8BfsVP4Q2wUUweGcd8O6ooqKajl6sDKKZJTRzu72CpLWemaDwXDXBSfPnnGwLMciTYUzxVYK8nRYPIKaBG6c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771361103; c=relaxed/simple; bh=+/toOdLHUqKt2waNa8BBWbkgYzgowdXPutJ6PcdxAoE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lVHKEsq7Y983tTNYREmmumXZj/WsvE3BmxSXgSvoPodJQynnN11bJia23zenCt+2KVIlKBIv12jbJ0QcqCdcj4ru/Qn8GxyHsbuD2XB9OMJSOCHeCX0IbSdvuTEonk3lQVqvaG50Owi3H5CjvaM6PxegrTTp9c90busMsdHj6po= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hcqydvPf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hcqydvPf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65C1EC4CEF7; Tue, 17 Feb 2026 20:45:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1771361102; bh=+/toOdLHUqKt2waNa8BBWbkgYzgowdXPutJ6PcdxAoE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hcqydvPfFgntaiKZOm4sETpUCRx0NAKWcRRHV4Ke7QixGwPXKCD9hFMATk9nXqJzS PXNS2m0fB0IXp9fTQ3RQn/hFFdD+0BnWEu10n4YQLatHU0/7yT73Zq4evsWJ8LBKa4 LGXTkFQCLRn6TVm38mpYz870mOYFU04cBpu/LGd8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Liu Song , Manivannan Sadhasivam , Bjorn Helgaas , stable@kernel.org, Sasha Levin Subject: [PATCH 5.15 34/39] PCI: endpoint: Avoid creating sub-groups asynchronously Date: Tue, 17 Feb 2026 21:31:43 +0100 Message-ID: <20260217200004.255999478@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260217200002.929083107@linuxfoundation.org> References: <20260217200002.929083107@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Greg Kroah-Hartman --- drivers/pci/endpoint/pci-ep-cfs.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) --- 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(st 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 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;