4.19-stable review patch. If anyone has any objections, please let me know.
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From: Peiyang Wang wangpeiyang1@huawei.com
[ Upstream commit df3dff8ab6d79edc942464999d06fbaedf8cdd18 ]
When the driver is uninstalled and the VF is disabled concurrently, a kernel crash occurs. The reason is that the two actions call function pci_disable_sriov(). The num_VFs is checked to determine whether to release the corresponding resources. During the second calling, num_VFs is not 0 and the resource release function is called. However, the corresponding resource has been released during the first invoking. Therefore, the problem occurs:
[15277.839633][T50670] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 ... [15278.131557][T50670] Call trace: [15278.134686][T50670] klist_put+0x28/0x12c [15278.138682][T50670] klist_del+0x14/0x20 [15278.142592][T50670] device_del+0xbc/0x3c0 [15278.146676][T50670] pci_remove_bus_device+0x84/0x120 [15278.151714][T50670] pci_stop_and_remove_bus_device+0x6c/0x80 [15278.157447][T50670] pci_iov_remove_virtfn+0xb4/0x12c [15278.162485][T50670] sriov_disable+0x50/0x11c [15278.166829][T50670] pci_disable_sriov+0x24/0x30 [15278.171433][T50670] hnae3_unregister_ae_algo_prepare+0x60/0x90 [hnae3] [15278.178039][T50670] hclge_exit+0x28/0xd0 [hclge] [15278.182730][T50670] __se_sys_delete_module.isra.0+0x164/0x230 [15278.188550][T50670] __arm64_sys_delete_module+0x1c/0x30 [15278.193848][T50670] invoke_syscall+0x50/0x11c [15278.198278][T50670] el0_svc_common.constprop.0+0x158/0x164 [15278.203837][T50670] do_el0_svc+0x34/0xcc [15278.207834][T50670] el0_svc+0x20/0x30
For details, see the following figure.
rmmod hclge disable VFs ---------------------------------------------------- hclge_exit() sriov_numvfs_store() ... device_lock() pci_disable_sriov() hns3_pci_sriov_configure() pci_disable_sriov() sriov_disable() sriov_disable() if !num_VFs : if !num_VFs : return; return; sriov_del_vfs() sriov_del_vfs() ... ... klist_put() klist_put() ... ... num_VFs = 0; num_VFs = 0; device_unlock();
In this patch, when driver is removing, we get the device_lock() to protect num_VFs, just like sriov_numvfs_store().
Fixes: 0dd8a25f355b ("net: hns3: disable sriov before unload hclge layer") Signed-off-by: Peiyang Wang wangpeiyang1@huawei.com Signed-off-by: Jijie Shao shaojijie@huawei.com Reviewed-by: Simon Horman horms@kernel.org Link: https://patch.msgid.link/20241101091507.3644584-1-shaojijie@huawei.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/hisilicon/hns3/hnae3.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/hisilicon/hns3/hnae3.c b/drivers/net/ethernet/hisilicon/hns3/hnae3.c index b250d0fe9ac50..1265010f063fe 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hnae3.c +++ b/drivers/net/ethernet/hisilicon/hns3/hnae3.c @@ -25,8 +25,11 @@ void hnae3_unregister_ae_algo_prepare(struct hnae3_ae_algo *ae_algo) pci_id = pci_match_id(ae_algo->pdev_id_table, ae_dev->pdev); if (!pci_id) continue; - if (IS_ENABLED(CONFIG_PCI_IOV)) + if (IS_ENABLED(CONFIG_PCI_IOV)) { + device_lock(&ae_dev->pdev->dev); pci_disable_sriov(ae_dev->pdev); + device_unlock(&ae_dev->pdev->dev); + } } } EXPORT_SYMBOL(hnae3_unregister_ae_algo_prepare);