CVE-2026-80985

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

net/smc: carry oversized SMC-Rv2 LLC messages in the queue entry

smc llc rmt delete rkey() and smc llc save add link rkeys() read the part of a v2 message that does not fit into the 44-byte union smc llc msg, and both bound themselves by the size of the buffer it landed in, not by what arrived. On a link with a shared v2 receive buffer a 44-byte DELETE RKEY V2 declaring 255 rkeys reaches rkey[9..254] in whatever an earlier message left in lgr->wr rx buf v2, and passes each of them to smc rtoken delete(). One of those 255 matched a registered rtoken and deleted it. An ADD LINK on such a link installs up to 255 rtokens from the same bytes.

Copy the tail into the queue entry, so its length is the length of the message that arrived, and declare the rkeys that fit inline as a member of the union instead of reaching them through a cast. The same DELETE RKEY V2 now processes the 9 rkeys it carries. The copy is limited to the longest tail the two functions can read, so the peer does not pick the size of the entry.

The bound the previous patch placed on links without a shared v2 receive buffer is no longer needed.