CVE-2024-50296

Summary

In the Linux kernel, the following vulnerability has been resolved:

net: hns3: fix kernel crash when uninstalling driver

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().

Affected Software

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

• SSVC:
• Exploitation: none
  • Automatable: no
  • Technical Impact: partial

CVE Program Container

Additional References

• https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html
• https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html

References

• https://git.kernel.org/stable/c/a0df055775f30850c0da8f7dab40d67c0fd63908
• https://git.kernel.org/stable/c/7ae4e56de7dbd0999578246a536cf52a63f4056d
• https://git.kernel.org/stable/c/590a4b2d4e0b73586e88bce9b8135b593355ec09
• https://git.kernel.org/stable/c/e36482b222e00cc7aeeea772fc0cf2943590bc4d
• https://git.kernel.org/stable/c/76b155e14d9b182ce83d32ada2d0d7219ea8c8dd
• https://git.kernel.org/stable/c/719edd9f3372ce7fb3b157647c6658672946874b
• https://git.kernel.org/stable/c/b5c94e4d947d15d521e935ff10c5a22a7883dea5
• https://git.kernel.org/stable/c/df3dff8ab6d79edc942464999d06fbaedf8cdd18

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