CVE-2022-48779

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

net: mscc: ocelot: fix use-after-free in ocelot_vlan_del()

ocelot_vlan_member_del() will free the struct ocelot_bridge_vlan, so if this is the same as the ports pvid_vlan which we access afterwards, what were accessing is freed memory.

Fix the bug by determining whether to clear ocelot_port->pvid_vlan prior to calling ocelot_vlan_member_del().

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.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/c98bed60cdd7f22237ae256cc9c1c3087206b8a2
• https://git.kernel.org/stable/c/ef57640575406f57f5b3393cf57f457b0ace837e
• https://git.kernel.org/stable/c/c98bed60cdd7f22237ae256cc9c1c3087206b8a2
• https://git.kernel.org/stable/c/ef57640575406f57f5b3393cf57f457b0ace837e