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

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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.

Fixes: ae2be35cbe ("net/smc: {at|de}tach sndbuf to peer DMB if supported")
Cc: stable@vger.kernel.org
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Reviewed-by: Sidraya Jayagond <sidraya@linux.ibm.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Link: https://patch.msgid.link/20260808-b4-disp-22f119e6-v2-1-61647601a6f3@proton.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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This commit is contained in:

Bryam Vargas 2026-08-08 02:21:23 -05:00 • committed by Jakub Kicinski

parent 3aa1dcaa4f

commit 36cdf5d48c

1 changed files with 7 additions and 6 deletions

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net/smc/smc_core.c

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