CVE-2026-89529

Summary

In the Linux kernel, the following vulnerability has been resolved:

svcrdma: Reject oversized Read segments at decode time

The RPC/RDMA Read list decoder stores wire-supplied segment lengths without validation. xdr_count_read_segments() checks 4-byte alignment for non-zero position values but does not cap the segment length.

An oversized rs_length reaches svc_rdma_build_read_segment(), which derives nr_bvec from it and can drive a large dynamic bvec allocation before verifying that enough rq_pages remain. If the post-allocation page-overrun guard fires, the freshly acquired rw context is not returned, leaking the resource.

Reject any segment whose length exceeds the receive context's page budget during Read list decoding, consistent with how xdr_check_write_chunk() bounds Write segment counts against rc_maxpages. Also return the rw context on the existing post-allocation overrun path in svc_rdma_build_read_segment(), keeping that defensive guard balanced.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux5ee62b4a91137557ee4b09d1604f1dfd0b4344a8 < 5120fe54e0e2f5b62797a432115cc61d61117a5baffected
LinuxLinux5ee62b4a91137557ee4b09d1604f1dfd0b4344a8 < af6f0e06bed818ee7fc8b869915964410020a1c5affected
LinuxLinux7.0affected
LinuxLinux0 < 7.0unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References