CVEvulnerability
CVE-2026-72469
8.8 HIGH
Official page ↗
- Status
- Received
- Published
- 2026-08-15
- Last modified
- 2026-10-21
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
- 8.8 HIGH — CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Description
In the Linux kernel, the following vulnerability has been resolved:
xprtrdma: Fix ep kref imbalance on ADDR_CHANGE
rpcrdma_cm_event_handler() falls through to the disconnected: label
on RDMA_CM_EVENT_ADDR_CHANGE and calls rpcrdma_ep_put() with no
matching get when the event arrives before RDMA_CM_EVENT_ESTABLISHED.
The kref then underflows during connect teardown and
rpcrdma_xprt_disconnect() operates on a freed ep.
Reference counts across a normal connection lifecycle:
rpcrdma_ep_create() kref_init ->1
rpcrdma_xprt_connect() ep_get ->2 (before post_recvs)
RDMA_CM_EVENT_ESTABLISHED ep_get ->3
RDMA_CM_EVENT_DISCONNECTED ep_put ->2
rpcrdma_xprt_drain() ep_put ->1
rpcrdma_xprt_disconnect() tail ep_put ->0 (ep_destroy)
The connect-time get in rpcrdma_xprt_connect(), taken just before
rpcrdma_post_recvs() "while there are outstanding Receives," is
balanced by rpcrdma_xprt_drain. ADDR_CHANGE before ESTABLISHED has
no get to consume, so its put drops the count to 1 and the drain
put then frees the ep while rpcrdma_xprt_disconnect() still holds a
pointer to it.
Fix by dispatching on the prior re_connect_status via xchg(): for
prev == 0 (pre-ESTABLISHED) wake the connect waiter and return with
no put; for prev == 1 call rpcrdma_force_disconnect() and return.
The case-1 arm relies on the subsequent RDMA_CM_EVENT_DISCONNECTED
event -- reliably delivered when rdma_disconnect() is called on a
still-connected cm_id -- to balance the ESTABLISHED get;
rpcrdma_xprt_drain() continues to balance only that connect-time
get. Any other prior value means teardown is already in flight.
References
- https://git.kernel.org/stable/c/a562485c359d0b20a99d466b042af9c2f7ff3326 git.kernel.org
- https://git.kernel.org/stable/c/af9b65b29af341932625c4283dc7a23cdb62688a git.kernel.org
- https://git.kernel.org/stable/c/cfd1bab66b042da7a778786685125656c695931b git.kernel.org
- https://git.kernel.org/stable/c/d0479c2b12974aa188b10d221a5770126b118b6d git.kernel.org
- https://git.kernel.org/stable/c/ffc07790539736a5d029f6a3c966b46c529f93a8 git.kernel.org