CVE-2026-80979

net/smc: unregister the connection before draining the rx tasklet

HIGH
7.8
CVSS Score
Published: September 11, 2026 at 07:42 PM UTC
Updated: October 19, 2026 at 09:17 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.8
Exploit prediction
EPSS 0.1%

Description

In the Linux kernel, the following vulnerability has been resolved: net/smc: unregister the connection before draining the rx tasklet smc_conn_free() calls smc_ism_unset_conn() only while the link group is still on its device list, and never sets conn->killed. smc_lgr_terminate_sched() unlinks the group immediately and defers killing its connections to a work item, so a connection freed in that window keeps its smcd->conn[] slot with both gates in smcd_handle_irq() open, and the device can re-arm the receive tasklet after tasklet_kill() has returned. On the DMB-nocopy path the ghost send buffer is freed right after that drain, so the re-armed tasklet dereferences it. Unregister unconditionally and drain before the detach at both teardown sites, mirroring rmb_desc, which smc_buf_unuse() releases after the drain. Clear conn->sndbuf_desc before freeing it as well, so a reader that samples the pointer cannot get one that is already freed.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

21f6f41e82e59740e26e06e77bdf58dc7f6f08dd6.106.6.66ae2be35cbed2c8385e890147ea321a3fcc3ca5fa
Vendor states this is fixed in 36cdf5d48ca191dcd71c28cadbe0981b1d25318d (fixed)
Vendor states this is fixed in 5bd8b764a610b6b6bc0c4d3d01652747f6e0b5c3 (fixed)
Vendor states this is fixed in b4d540ac95cd35c6ebab6afb7eae2bcac7b277a5 (fixed)
Vendor states this is fixed in b6b6ac713ee82b340a8e3be30b101bd2840deec4 (fixed)
Vendor states this is fixed in b74d313567dfc1b7e56629ddbad04e728686f235 (fixed)
Vendor states this is fixed in 6.10 (unaffected)
Vendor states this is fixed in 6.12.109 (unaffected)
Vendor states this is fixed in 6.18.50 (unaffected)
Vendor states this is fixed in 6.6.157 (unaffected)
Vendor states this is fixed in 7.2.4 (unaffected)
Vendor states this is fixed in 7.3 (unaffected)
Vendor states this is fixed in 7.3-rc1 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

CVSS

7.8HIGHLinux
Vector?

Quick Info

StatusRECEIVED

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