Bug 2532124 (CVE-2026-80980)

Summary: CVE-2026-80980 kernel: net/smc: stop killed, freed and out_of_sync sharing a byte
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's SMC (Server Message Block over Remote Direct Memory Access) protocol implementation. A concurrency issue exists where three connection state flags (killed, freed, and out_of_sync) share a single byte in the `smc_connection` structure without proper locking mechanisms. This allows for a read-modify-write race condition when different functions attempt to modify these flags simultaneously. This could lead to incorrect connection state management, potentially causing unexpected behavior or a denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-11 20:46:25 UTC
In the Linux kernel, the following vulnerability has been resolved:

net/smc: stop killed, freed and out_of_sync sharing a byte

The three connection state flags are single-bit bitfields, so they occupy
one byte of struct smc_connection and every store to one is a
read-modify-write of the other two:

    u8  killed : 1;
    u8  freed : 1;
    u8  out_of_sync : 1;

They are not written under a common lock. smc_cdc_msg_validate() sets
out_of_sync from the receive tasklet, while smc_conn_kill() sets killed
from process context under lock_sock(), and the receive path does not defer
to the backlog when the socket is owned -- smc_cdc_msg_recv() takes only
bh_lock_sock().

Give each flag its own byte so a store no longer touches its neighbours.
All readers test them as booleans and are unchanged. struct smc_connection
grows by two bytes.