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 C8E8F54723; Fri, 13 Feb 2026 13:54:21 +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=1770990861; cv=none; b=hpLoqk0d5fkwYUqxVz1d3on/aFKN0sqEp7aYAO5lBFeSnr1x7fXZM9kyipj2RL257zcmPJUQT2Ku0Q2ad+NhRreyBNSHBHcHYwsybXICgHdjPi5tvsCuB4HlyPKN5dBy0cJYldWF71ZGyFxqXyTFbibdXz7SLHuKLqmxMqTcBRI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770990861; c=relaxed/simple; bh=Bi9gNILnmj8V0kanKC7nAIz27wk5aS75jjXl+27wmn8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GUZYJSsRYk4dBDZ7VzchLrgHFxJepJraGcBF3499SSo27aPz8dBrQIKqNZZKfeT7FtZ19D2dU+6gSr4P4dLsmldNzUVBP4KJftpbwCHYkr+FBRSB1I4yRLu6QaT+pY730FLScbB2w/S8Jf+zZuiTd2imLdJaLfzHGvMw+Z+V8O4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MnyVmByk; 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="MnyVmByk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F30DC116C6; Fri, 13 Feb 2026 13:54:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1770990861; bh=Bi9gNILnmj8V0kanKC7nAIz27wk5aS75jjXl+27wmn8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MnyVmBykL42ApTyghBOn0HEb2QhZBYyEkNpqVyG7Byd7+e2hdfm/BaSx/Xot2ZwN4 OxfomJPV062TfK0xv2UCltnWa2EEsQiNGO60TRraj61WWYJfTgFWbvisIFjGaIUGtD jpK3ncZKxqg3W6Dj13Lm494XMlqpjhnOPZfii2x4= 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 Subject: [PATCH 6.18 47/49] PCI: endpoint: Avoid creating sub-groups asynchronously Date: Fri, 13 Feb 2026 14:48:31 +0100 Message-ID: <20260213134710.582432558@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260213134708.885500854@linuxfoundation.org> References: <20260213134708.885500854@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Liu Song commit 7c5c7d06bd1f86d2c3ebe62be903a4ba42db4d2c upstream. 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: 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; }; @@ -103,7 +102,7 @@ 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; } @@ -166,7 +165,7 @@ 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; } @@ -570,15 +569,13 @@ 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"); @@ -637,9 +634,7 @@ 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;