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.

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History

Sat, 12 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-125
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.7, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:H'}

threat_severity

Moderate


Fri, 11 Sep 2026 23:45:00 +0000

Type Values Removed Values Added
Description 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.
Title net/smc: carry oversized SMC-Rv2 LLC messages in the queue entry
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-11T19:42:44.243Z

Reserved: 2026-08-26T14:34:25.811Z

Link: CVE-2026-80985

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-11T20:19:05.050

Modified: 2026-09-11T20:19:05.050

Link: CVE-2026-80985

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-11T19:42:44Z

Links: CVE-2026-80985 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses