CVE-2026-64269

CVE CVE-2026-64269EUVD EUVD-2026-48981Veröffentlicht 2026-07-25T08:49:16.000ZZuletzt geändert 2026-08-05T12:40:26.000ZCVSS 9.1

Was das Advisory beschreibt

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 field that was not checked against the chunk size. A peer that advertises desc[0].len larger than max_chunk_size can make the posted RDMA write read past the chunk's mapped region. The resulting behaviour depends on the IOMMU configuration: with no IOMMU or in passthrough mode the read may extend into memory adjacent to the chunk and be returned to the peer, which can disclose host memory; with a translating IOMMU the out-of-range access is expected to fault and abort the connection. In either case the transfer exceeds what the protocol permits and is driven by a remote peer. Reject a descriptor length above max_chunk_size, mirroring the existing off >= max_chunk_size bound in rtrs_srv_rdma_done(). Legitimate clients do not exceed it: the client sets desc[0].len to its MR length, which is capped at the negotiated max_io_size (max_chunk_size - MAX_HDR_SIZE).

Quelle: EUVD (ENISA), im Wortlaut der Meldung.

Produkte, die das Advisory nennt

Diese Angaben stammen aus der Meldung selbst, nicht aus einer Prüfung durch uns.

• Linux — Linux 9cb837480424e78ed585376f944088246685aec3 <5a45d0aa1fa50a333ce5763ade744e2d89838667; patch: 6.1.178; 9cb837480424e78ed585376f944088246685aec3 <68c09762172f6224e9ddf9b0a60bacbb36e443eb; 9cb837480424e78ed585376f944088246685aec3 <6cada540150894e81042a0ae0c796a21a9a877da; patch: 6.12.96; patch: 6.6.145; patch: 7.1.4; patch: 6.18.39; patch: 5.15.212; 9cb837480424e78ed585376f944088246685aec3 <2912f3d40355dabc08fdbaaf2764d02445fe88dc; 5.8; 9cb837480424e78ed585376f944088246685aec3 <da3e44add94b05dfde56f898421922f5cf35705f; 9cb837480424e78ed585376f944088246685aec3 <963af8d97a8c6a117134a8d0db1415e0489200b1; patch: 0; 9cb837480424e78ed585376f944088246685aec3 <6f40246f4312fdbab5a13cc440adebf95eb2aa66; patch: 7.2-rc1

Die genannten Versionen sind die Angabe der Meldung. Patchlage vergleicht keine Versionsnummern und leitet aus ihnen keine Aussage ab — welche Version installiert ist, muss ein Mensch nachsehen.

Im Produktkatalog geführt

Für diese Produkte kann ein Bestand in Patchlage erfasst werden. Ein Advisory dazu erscheint am Morgen danach im Lagebericht.

• Linux — Linux

Patchlage meldet Treffer und Verdachtsfälle. Zu allem anderen sagt dieses System nichts — weder diese Seite noch der Lagebericht behauptet je, dass ein Bestand sicher ist.