Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Reorder rpcrdma_rn_unregister before rdma_destroy_id
svc_rdma_free() caches rdma->sc_cm_id->device before teardown, then calls rdma_destroy_id(sc_cm_id) which frees the cm_id. rpcrdma_rn_unregister() follows, but between those two calls the transport’s sc_rn entry is still installed in the device’s rd_xa. A concurrent ib_unregister_device walk can dispatch svc_rdma_xprt_done() against the now-freed sc_cm_id.
Move rpcrdma_rn_unregister() before rdma_destroy_id() so the transport’s notification entry is removed from the xarray before the cm_id it references is destroyed.
Also guard the sc_cm_id dereference with a NULL check: the following patches introduce paths that reach svc_rdma_free() with sc_cm_id == NULL (listener create failure, ADDR_CHANGE replacement failure).
Details
- Affected product:
- Debian 10 ELS , Debian 11 ELS
- Affected packages:
- linux @ 5.10.259 (+1 more)