CVE-2026-64269
CVE-2026-64269CVE-2026-64269
Description
In the Linux kernel, the following vulnerability has been resolved:
RDMA/rtrs-srv: Bound RDMA-Write length to chunk size in rdma_write_sg
When the server answers an RTRS READ, rdma_write_sg() builds the source
scatter/gather entry for the IB_WR_RDMA_WRITE that returns data to the
peer. Its length is taken directly from the wire descriptor:
plist->length = le32_to_cpu(id->rd_msg->desc[0].len);
rd_msg points into the chunk buffer that the remote peer filled via
RDMA-WRITE-WITH-IMM (rtrs_srv_rdma_done() -> process_io_req() ->
process_read()), so desc[0].len is attacker-controlled and, before this
change, was only rejected when zero. The source address is the fixed
chunk start (dma_addr[msg_id]) and the source lkey is the PD-wide
local_dma_lkey, which is not tied to the chunk's MR mapping, so the verbs
layer does not constrain the transfer length to max_chunk_size. msg_id
and off are bounded against queue_depth and max_chunk_size in
rtrs_srv_rdma_done(), but desc[0].len is a separate
Scoring
| Last modified | 2026-07-25 |