From nobody Wed Feb 11 05:11:02 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 2AF1F347FD2; Tue, 16 Dec 2025 08:13:19 +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=1765872803; cv=none; b=Ufysem3HZW9BCwoJjIH98bgphYYzH+FGkKQq/37Mop227LAnw9yHZpa+GbUiokzjHOuyitTXT9sR/D6elCwkl2MbHgUddWebnRI655CR/Zs4dSk4T9zxf5qXCS3Hzfqarpa6/D2L0ay3x0LbxJmNtQecbrtD+wYjhXUogW9G7Yg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765872803; c=relaxed/simple; bh=MuTAF4fOLJk3khpF9NmDB9Q/WyViABe0U7dwSkkBHeU=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=czfinxhHTUKC1w/mfuNnjD/xKDZBakyTv2GIzzsdDt9R7QYQ/7aiOho235qp3iXZ4vrIV8bfn71CBeAv7TG0MLfi6iWdE5MFLtES0UPVuIVYh9lpF8Vcn1QrgtyB065hN8DKTO83ARzSORFYvL/q8V/mqd6j3ejrUSPm7f0x+2k= 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=WFvvD/fe; 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="WFvvD/fe" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=BbVtg0J6THxhxcDCFoLlMEcYnobUuiVC/Whu7LrnJVI=; b=WFvvD/feMqWMFktjsNUYtn7DnS5lmWEo5JbfZgsHErgVC6j6Srr2GSSHjrZ/7fm/5FfOV94GA DiVUU8Z3ARP+aHHasuOhJjriL24j6RQqOuruH11NMZzSc9cciwb2hvyB8Rg/dfQOApvWL9WRFL7 CxpkXmx5k8NYbLrj/TDjT0I= Received: from mail.maildlp.com (unknown [172.19.88.105]) by canpmsgout05.his.huawei.com (SkyGuard) with ESMTPS id 4dVqPg4Zyxz12LDy; Tue, 16 Dec 2025 16:11:03 +0800 (CST) Received: from kwepemr500012.china.huawei.com (unknown [7.202.195.23]) by mail.maildlp.com (Postfix) with ESMTPS id ED90A1402C8; Tue, 16 Dec 2025 16:13:17 +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; Tue, 16 Dec 2025 16:13:17 +0800 From: Ziming Du To: CC: , , , , , , Subject: [PATCH 1/3] PCI/sysfs: fix null pointer dereference during PCI hotplug Date: Tue, 16 Dec 2025 16:39:10 +0800 Message-ID: <20251216083912.758219-2-duziming2@huawei.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251216083912.758219-1-duziming2@huawei.com> References: <20251216083912.758219-1-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 atte= mpt 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 wh= en 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 0000000= 000000000 Mem abort info: ESR =3D 0x0000000096000004 EC =3D 0x25: DABT (current EL), IL =3D 32 bits SET =3D 0, FnV =3D 0 EA =3D 0, S1PTW =3D 0 FSC =3D 0x04: level 0 translation fault Data abort info: ISV =3D 0, ISS =3D 0x00000004, ISS2 =3D 0x00000000 CM =3D 0, WnR =3D 0, TnD =3D 0, TagAccess =3D 0 GCS =3D 0, Overlay =3D 0, DirtyBit =3D 0, Xs =3D 0 user pgtable: 4k pages, 48-bit VAs, pgdp=3D000020400d47b000 0000000000000000 pgd=3D0000000000000000, p4d=3D0000000000000000 Internal error: Oops: 0000000096000004 #1 SMP CPU: 115 PID: 13659 Comm: testEL_vf_resca Kdump: loaded Tainted: G W E 6.6.= 0 #9 Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 0.98 08/25/2019 pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=3D--) pc : __pi_strlen+0x14/0x150 lr : kernfs_name_hash+0x24/0xa8 sp : ffff8001425c38f0 x29: ffff8001425c38f0 x28: ffff204021a21540 x27: 0000000000000000 x26: 0000000000000000 x25: 0000000000000000 x24: ffff20400f97fad0 x23: ffff20403145a0c0 x22: 0000000000000000 x21: 0000000000000000 x20: 0000000000000000 x19: 0000000000000000 x18: ffffffffffffffff x17: 2f35322f38302038 x16: 392e3020534f4942 x15: 00000000fffffffd x14: 0000000000000000 x13: 30643378302f3863 x12: 3378302b636e7973 x11: 00000000ffff7fff x10: 0000000000000000 x9 : ffff800100594b3c x8 : 0101010101010101 x7 : 0000000000210d00 x6 : 67241f72241f7224 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 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