CVE-2026-80981

/// Technical description

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

net/smc: fix use-after-free of the LLC qentry in smc_llc_srv_add_link()

smc_llc_srv_add_link() keeps add_llc pointing into the queue entry:

add_llc = &qentry->msg.add_link; smc_llc.c:1482

...

smc_llc_save_add_link_info(link_new, add_llc); smc_llc.c:1494

smc_llc_flow_qentry_del(&lgr->llc_flow_lcl); smc_llc.c:1495

...

u8 *llc_msg = smc_link_shared_v2_rxbuf(link) ?

(u8 *)lgr->wr_rx_buf_v2 : (u8 *)add_llc; smc_llc.c:1504

smc_llc_save_add_link_rkeys(link, link_new, llc_msg); smc_llc.c:1506

smc_llc_flow_qentry_del() kfree()s the entry, so on a link without a shared

v2 receive buffer the pointer handed to smc_llc_save_add_link_rkeys() is

already freed. Before the Fixes: commit that branch always used

lgr->wr_rx_buf_v2 and add_llc was not used after the free.

Reproduced on an unpatched tree over rxe, with KASAN, kasan_multi_shot

and a link forced to max_recv_sge == 1: the entry is freed and read by

the s

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References