Linux vulnerability

What happened

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 versions

Linux: ae2be35cbed2c8385e890147ea321a3fcc3ca5fa through before b4d540ac95cd35c6ebab6afb7eae2bcac7b277a5 (git); ae2be35cbed2c8385e890147ea321a3fcc3ca5fa through before 5bd8b764a610b6b6bc0c4d3d01652747f6e0b5c3 (git); ae2be35cbed2c8385e890147ea321a3fcc3ca5fa through before b74d313567dfc1b7e56629ddbad04e728686f235 (git); ae2be35cbed2c8385e890147ea321a3fcc3ca5fa through before 36cdf5d48ca191dcd71c28cadbe0981b1d25318d (git); 21f6f41e82e59740e26e06e77bdf58dc7f6f08dd (git); 6.6.66 through before 6.7 (semver); 6.10 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.