From nobody Tue Feb 10 07:41:05 2026 Received: from canpmsgout05.his.huawei.com (canpmsgout05.his.huawei.com [113.46.200.220]) (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 753FE30B529; Wed, 24 Dec 2025 09:01:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.220 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766566907; cv=none; b=YX64qAGDbvLJ6Jgxk7rCMgyRi5QjsbrlaMviAipVdddEgYmKSqFU7LUexZ6dFEH6I8oDt886Ftpyu+Hkud00gizilwlMKI/BT0GnOIuP78D2I8hanRnqFCyXf6d8cboX8eVoRhBI1voOBd09HvNbigVeTNp5vC5TRHAgXkGRwkE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766566907; c=relaxed/simple; bh=IdhHESCbfV4q37Zk9vcG4CJ1b0S9nmD+dObf1YGwhrw=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=YQI83Pt1pkIunIsP69V6vf6D2KkP2o+naxQTIEEyx49kuF0SLcDRTsokczR6lhQDv3xKg941SD8IZTyLif/j6pb4CRAZSiJm4EAV72rZayHXddxcmXIhRZly4Vp1DMiOLd7+0eeh1a9w9/ey5NPtFGSPVQvI1lqtMZSd0gJ60eg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=JrRlnldj; arc=none smtp.client-ip=113.46.200.220 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="JrRlnldj" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=3zzZNBQowhMsIB/7RZytqeIdQImGje7POVm8OpbwEG4=; b=JrRlnldjD12qHhlyDRBsCCHXi5N6xT6c4SKTN0L1nEBVDHkCE5neZxU1ghIl3+apUebH81G+h W3g9qCRryXk/9svbNIg6w1gZbLDiuGwakbSLu5zd3jsBxAuI6i2Ny3J5bQ1ogI1gxbqqm0fN+Fc jktXraLJqKNEUT1QhHNYQK0= Received: from mail.maildlp.com (unknown [172.19.162.140]) by canpmsgout05.his.huawei.com (SkyGuard) with ESMTPS id 4dbm4h69cxz12LKW; Wed, 24 Dec 2025 16:58:28 +0800 (CST) Received: from kwepemr500012.china.huawei.com (unknown [7.202.195.23]) by mail.maildlp.com (Postfix) with ESMTPS id 43C7320104; Wed, 24 Dec 2025 17:01:41 +0800 (CST) Received: from localhost.localdomain (10.50.85.180) by kwepemr500012.china.huawei.com (7.202.195.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 24 Dec 2025 17:01:40 +0800 From: Ziming Du To: , , , CC: , , , Subject: [PATCH v2 1/3] PCI/sysfs: Fix null pointer dereference during hotplug Date: Wed, 24 Dec 2025 17:27:17 +0800 Message-ID: <20251224092721.2034529-2-duziming2@huawei.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251224092721.2034529-1-duziming2@huawei.com> References: <20251224092721.2034529-1-duziming2@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: kwepems200002.china.huawei.com (7.221.188.68) To kwepemr500012.china.huawei.com (7.202.195.23) Content-Type: text/plain; charset="utf-8" During the concurrent process of creating and rescanning in VF, the resource files for the same pci_dev may be created twice. The second creation attempt fails, resulting the res_attr in pci_dev to kfree(), but the pointer is not set to NULL. This will subsequently lead to dereferencing a null pointer when removing the device. When we perform the following operation: echo $vfcount > /sys/class/net/"$pfname"/device/sriov_numvfs & sleep 0.5 echo 1 > /sys/bus/pci/rescan pci_remove "$pfname" system will crash as follows: Unable to handle kernel NULL pointer dereference at virtual address 00000= 00000000000 Call trace: __pi_strlen+0x14/0x150 kernfs_find_ns+0x54/0x120 kernfs_remove_by_name_ns+0x58/0xf0 sysfs_remove_bin_file+0x24/0x38 pci_remove_resource_files+0x44/0x90 pci_remove_sysfs_dev_files+0x28/0x40 pci_stop_bus_device+0xb8/0x118 pci_stop_and_remove_bus_device+0x20/0x40 pci_iov_remove_virtfn+0xb8/0x138 sriov_disable+0xbc/0x190 pci_disable_sriov+0x30/0x48 hinic_pci_sriov_disable+0x54/0x138 [hinic] hinic_remove+0x140/0x290 [hinic] pci_device_remove+0x4c/0xf8 device_remove+0x54/0x90 device_release_driver_internal+0x1d4/0x238 device_release_driver+0x20/0x38 pci_stop_bus_device+0xa8/0x118 pci_stop_and_remove_bus_device_locked+0x28/0x50 remove_store+0x128/0x208 Fix this by set the pointer to NULL after releasing res_attr immediately. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Ziming Du --- drivers/pci/pci-sysfs.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index c2df915ad2d2..7e697b82c5e1 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -1222,12 +1222,14 @@ static void pci_remove_resource_files(struct pci_de= v *pdev) if (res_attr) { sysfs_remove_bin_file(&pdev->dev.kobj, res_attr); kfree(res_attr); + pdev->res_attr[i] =3D NULL; } =20 res_attr =3D pdev->res_attr_wc[i]; if (res_attr) { sysfs_remove_bin_file(&pdev->dev.kobj, res_attr); kfree(res_attr); + pdev->res_attr_wc[i] =3D NULL; } } } --=20 2.43.0