CVE-2022-48861

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

vdpa: fix use-after-free on vp_vdpa_remove

When vp_vdpa driver is unbind, vp_vdpa is freed in vdpa_unregister_device and then vp_vdpa->mdev.pci_dev is dereferenced in vp_modern_remove, triggering use-after-free.

Call Trace of unbinding driver free vp_vdpa : do_syscall_64 vfs_write kernfs_fop_write_iter device_release_driver_internal pci_device_remove vp_vdpa_remove vdpa_unregister_device kobject_release device_release kfree

Call Trace of dereference vp_vdpa->mdev.pci_dev: vp_modern_remove pci_release_selected_regions pci_release_region pci_resource_len pci_resource_end (dev)->resource[(bar)].end

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/4b1743bc715a3691a63ac21b349079b07bf1b19e
• https://git.kernel.org/stable/c/dc54ba9932aeaaa1a21fe214af1f446593a78274
• https://git.kernel.org/stable/c/eb057b44dbe35ae14527830236a92f51de8f9184
• https://git.kernel.org/stable/c/4b1743bc715a3691a63ac21b349079b07bf1b19e
• https://git.kernel.org/stable/c/dc54ba9932aeaaa1a21fe214af1f446593a78274
• https://git.kernel.org/stable/c/eb057b44dbe35ae14527830236a92f51de8f9184