CVE-2026-53186: RDMA/srp: bound SRP_RSP sense copy by the received length

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

RDMA/srp: bound SRPRSP sense copy by the received length

srpprocessrsp() copies sense data from rsp->data + respdatalen, where respdatalen is the full 32-bit value supplied by the SRP target and is never checked against the number of bytes actually received (wc->bytelen). The copy length is bounded to SCSISENSEBUFFERSIZE, so at most 96 bytes are copied, but the source offset is not bounded.

A malicious or compromised SRP target on the InfiniBand/RoCE fabric that the initiator has logged into can return an SRPRSP with SRPRSPFLAGSNSVALID set and a large respdatalen. The receive buffer is allocated at the target-chosen maxtiiulen, so the source of the sense copy lands past the bytes actually received; with respdatalen near 0xFFFFFFFF it is gigabytes past the buffer and the read faults.

Copy the sense data only if it has not been truncated, that is, only if the response header, the response data, and the sense region fit within the bytes actually received; otherwise drop the sense and log. The in-tree iSER and NVMe-RDMA receive paths already bound their parse by wc->bytelen; this brings ibsrp into line with them.