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 2216134A3A7 for ; Fri, 13 Feb 2026 12:14:12 +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=1770984852; cv=none; b=XLncTpfGn1sYrooEqHhUEuZ7mswiOJa6KOGeW85m4oBvM9dxnCHop/xJ+IdVwsiwjNfvH67LUjalGOdfL3/rE3w99YisRmS7q/zzm6dBk39I3S6pnK/Ims7Ev8ECx+MCBDDPkPqHMZLUbT7tI/9/uGxJmL8LXBVXUTiRrj6kbGk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770984852; c=relaxed/simple; bh=+ErKUSWbJ2esJjnO+/ZE/z78vJzZmPCzwd4sugrHRyk=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=EnxDlJ0+oS3Q8OX52ewlRKI65qtD8ZDH3H8OMjKucpDc4DJgktzDr2xyyRWcrl80TtwgNIsELwcEiO3x2mcyYPeEXlQs/JgKfYQJwszbAGRfrz1s28g9bdmy/3i6dVo0hJmf48KYcDOnzVQFsSj7GXUfHp3GvmKlQmG/hso6bhg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Q9CoyOyY; 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="Q9CoyOyY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E7D8C116C6; Fri, 13 Feb 2026 12:14:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1770984851; bh=+ErKUSWbJ2esJjnO+/ZE/z78vJzZmPCzwd4sugrHRyk=; h=Subject:To:Cc:From:Date:From; b=Q9CoyOyYPzSgZ+qFD4vMj5ztxOSZ8+Xpt19TcHkipy3pC0gZkdSab5Vo6rlNYarz7 MVMa8lIULvojeHjVgj76cZmzknPYieewsgkAy2Sodd+PppJTu6hqd0Q5neMgSAIudv DNDCyQWhcc4QSgQj5Cq4oZN2oE5gKRlYVIG7wHyE= Subject: FAILED: patch "[PATCH] PCI: endpoint: Avoid creating sub-groups asynchronously" failed to apply to 6.6-stable tree To: liu.song13@zte.com.cn,bhelgaas@google.com,mani@kernel.org Cc: From: Date: Fri, 13 Feb 2026 13:14:03 +0100 Message-ID: <2026021303-salt-retread-63e7@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 7c5c7d06bd1f86d2c3ebe62be903a4ba42db4d2c # git commit -s git send-email --to '' --in-reply-to '2026021303-salt-retread-63e7@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 7c5c7d06bd1f86d2c3ebe62be903a4ba42db4d2c Mon Sep 17 00:00:00 2001 From: Liu Song Date: Thu, 10 Jul 2025 14:38:45 +0800 Subject: [PATCH] PCI: endpoint: Avoid creating sub-groups asynchronously 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 diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c index ef50c82e647f..43feb6139fa3 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; }; @@ -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(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"); @@ -637,9 +634,7 @@ 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;