CVE-2026-98354: RDMA/mad: Fix receive buffer leak when PKey enforcement fails

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-06 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/mad: Fix receive buffer leak when PKey enforcement fails ib_mad_complete_recv() initializes mad_recv_wc->rmpp_list and then runs ib_mad_enforce_security() before linking recv_buf onto that list. On failure it calls ib_free_recv_mad(), which only walks rmpp_list and frees the ib_mad_private of every buffer found there. As the list is still empty at that point, nothing is freed at all. The caller cannot clean up either: ib_mad_recv_done() sets recv to NULL right after ib_mad_complete_recv() returns, assuming the MAD layer took ownership of the buffer. Every MAD that fails the PKey check therefore leaks one ib_mad_private (about 300 bytes per IB port MAD, ~2K for OPA), and a remote node can trigger this repeatedly by sending MADs with a wrong PKey. Link recv_buf onto rmpp_list right after the list is initialized, so the error path has something to free.

Affected products

Linux kernel: 4.13 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

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