Description
In the Linux kernel, the following vulnerability has been resolved: xfrm: save input state data before secpath resets xfrm_input() stores the current xfrm_state in the skb secpath while it continues receive-side processing. Some input paths can reset that secpath before xfrm_input() has finished dereferencing the state. Receive callback users such as VTI and XFRM interfaces can reset the secpath. The VTI receive path does so before checking whether the packet crosses network namespaces, while the XFRM interface path does so only for cross-network-namespace packets. The XFRM_MAX_DEPTH error path can also reset the secpath before the final drop callback reports the current state's protocol. If secpath_reset() drops the last state reference while the state is concurrently deleted, xfrm_input() can still dereference the freed state when selecting transport_finish() or reporting the drop callback protocol. Save the state protocol on the stack while the state is still valid, and use the already saved address family for transport_finish(). A larval XFRM_STATE_ACQ state has no type, so retain nexthdr as its protocol. This preserves the existing drop-path fallback while avoiding the post-reset state dereferences without adding an extra state reference to every received packet.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
df3893c176e9b0bb39b28ab5ec8113fa20ad1ee0 to < 35de97850987b3d022ed17df5b2577242e746dafaffecteddf3893c176e9b0bb39b28ab5ec8113fa20ad1ee0 to < 148db154066b066616b82c12d373e786eba1f96aaffecteddf3893c176e9b0bb39b28ab5ec8113fa20ad1ee0 to < 537a5ae18b2be70f8eb0aca843682e81a69aab91affecteddf3893c176e9b0bb39b28ab5ec8113fa20ad1ee0 to < 3cf5cdecd99c9c186a5ea518d93bbf3045b6e3aaaffected
Linux Linux
Default version status: affected
3.15affected0 to < 3.15unaffected6.12.112 to ≤ 6.12.*unaffected6.18.54 to ≤ 6.18.*unaffected7.2.8 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected