CVE-2026-80979

Summary

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 Software

VendorProductVersion RangeStatus
LinuxLinuxae2be35cbed2c8385e890147ea321a3fcc3ca5fa < b4d540ac95cd35c6ebab6afb7eae2bcac7b277a5affected
LinuxLinuxae2be35cbed2c8385e890147ea321a3fcc3ca5fa < 5bd8b764a610b6b6bc0c4d3d01652747f6e0b5c3affected
LinuxLinuxae2be35cbed2c8385e890147ea321a3fcc3ca5fa < b74d313567dfc1b7e56629ddbad04e728686f235affected
LinuxLinuxae2be35cbed2c8385e890147ea321a3fcc3ca5fa < 36cdf5d48ca191dcd71c28cadbe0981b1d25318daffected
LinuxLinux21f6f41e82e59740e26e06e77bdf58dc7f6f08ddaffected
LinuxLinux6.6.66 < 6.7affected
LinuxLinux6.10affected
LinuxLinux0 < 6.10unaffected
LinuxLinux6.12.109 <= 6.12.*unaffected
LinuxLinux6.18.50 <= 6.18.*unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References