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.