CVE-2026-72465: xprtrdma: Sanitize the reply credit grant after parsing
In the Linux kernel, the following vulnerability has been resolved:
xprtrdma: Sanitize the reply credit grant after parsing
The outnorqst exit in rpcrdmareplyhandler() branches away before the credit clamp, so a reply that matches no pending request reaches outpost carrying the raw credit value parsed from the wire. rpcrdmapostrecvs() does not bound its @needed argument: the refill loop allocates and chains Receive WRs until the count is satisfied or allocation fails. A peer that sends a well-formed reply carrying an unknown XID and an inflated credit grant therefore drives rep allocation and Receive posting past remaxrequests on every such reply.
Move the clamp to immediately after the credit field is parsed, ahead of the first branch that can reach outpost, so every later consumer sees a sanitized value. The cwnd update stays on the matched-request path.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
Apply the fix described in the xprtrdma: Sanitize the reply credit grant after parsing change by ensuring the reply credit value parsed from the wire is clamped immediately after the credit field is parsed, so later Receive posting past re_max_requests and inflated credit grants cannot occur.