Affected: Alpaquita:23: linux-lts, Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

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

svcrdma: Validate Read chunk positions before reconstruction

The RPC/RDMA Read chunk position field is supplied by the remote client and stored verbatim in the parsed chunk list. xdr_count_read_segments() checks only 4-byte alignment; it never compares the position against the received inline body length.

In the single-chunk path, svc_rdma_read_complete_one() splits the head and tail kvecs at ch_position. A position past the inline body underflows the tail length, exposing adjacent slab memory to the upper XDR decoder.

In the multi-chunk path, svc_rdma_read_multiple_chunks() computes gap lengths between chunks as unsigned subtractions from ch_position. Overlapping Read chunks cause these subtractions to underflow. A final position past the inline body likewise underflows the trailing gap length. svc_rdma_copy_inline_range() then copies past the receive buffer into request pages that are returned to the client through the Reply channel.

Bound inline-range copies in svc_rdma_copy_inline_range() against the decoded inline RPC body saved in rc_saved_arg. Reject a single Read chunk positioned beyond that body, and reject multi-chunk lists where accumulated read bytes exceed the next chunk's position. Apply the same position and overlap checks in the call-chunk interleaving path.

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

svcrdma: Validate Read chunk positions before reconstruction

The RPC/RDMA Read chunk position field is supplied by the remote client and stored verbatim in the parsed chunk list. xdr_count_read_segments() checks only 4-byte alignment; it never compares the position against the received inline body length.

In the single-chunk path, svc_rdma_read_complete_one() splits the head and tail kvecs at ch_position. A position past the inline body underflows the tail length, exposing adjacent slab memory to the upper XDR decoder.

In the multi-chunk path, svc_rdma_read_multiple_chunks() computes gap lengths between chunks as unsigned subtractions from ch_position. Overlapping Read chunks cause these subtractions to underflow. A final position past the inline body likewise underflows the trailing gap length. svc_rdma_copy_inline_range() then copies past the receive buffer into request pages that are returned to the client through the Reply channel.

Bound inline-range copies in svc_rdma_copy_inline_range() against the decoded inline RPC body saved in rc_saved_arg. Reject a single Read chunk positioned beyond that body, and reject multi-chunk lists where accumulated read bytes exceed the next chunk's position. Apply the same position and overlap checks in the call-chunk interleaving path.

kernel-devel-7.2.7-1.1 on GA media

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 193 more

In the Linux kernel, the following vulnerability has been resolved: svcrdma: Validate Read chunk positions before reconstruction The RPC/RDMA Read chunk position field is supplied by the remote client and stored verbatim in the parsed chunk list. xdr_count_read_segments() checks only 4-byte alignment; it never compares the position against the received inline body length. In the single-chunk path, svc_rdma_read_complete_one() splits the head and tail kvecs at ch_position. A position past the inline body underflows the tail length, exposing adjacent slab memory to the upper XDR decoder. In the multi-chunk path, svc_rdma_read_multiple_chunks() computes gap lengths between chunks as unsigned subtractions from ch_position. Overlapping Read chunks cause these subtractions to underflow. A final position past the inline body likewise underflows the trailing gap length. svc_rdma_copy_inline_range() then copies past the receive buffer into request pages that are returned to the client through the Reply channel. Bound inline-range copies in svc_rdma_copy_inline_range() against the decoded inline RPC body saved in rc_saved_arg. Reject a single Read chunk positioned beyond that body, and reject multi-chunk lists where accumulated read bytes exceed the next chunk's position. Apply the same position and overlap checks in the call-chunk interleaving path.

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um Sicherheitsmaßnahmen zu umgehen, Daten oder den Systemzustand zu manipulieren, Denial-of-Service-Zustände herbeizuführen oder andere, nicht näher spezifizierte Angriffe durchzuführen.