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

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

xprtrdma: Check frwr_wp_create() during connect

frwr_wp_create() creates the singleton Memory Region used to encode padding for Write chunks whose payload length is not XDR-aligned. Its failure paths return a negative errno and leave ep->re_write_pad_mr set to NULL.

rpcrdma_xprt_connect() currently ignores that return value. If frwr_wp_create() fails after the rest of the connection setup succeeds, xprt_rdma_connect_worker() treats the connection attempt as successful and sets XPRT_CONNECTED. A later NFS/RDMA read with a non-4-byte-aligned receive page length reaches rpcrdma_encode_write_list(), passes the NULL write-pad MR to encode_rdma_segment(), and dereferences it.

This is locally triggerable on an NFS/RDMA client after a connect or reconnect hits a local MR allocation, DMA-map, MR-map, or post-send failure; a remote peer alone cannot force the local MR setup failure.

Check the return value and fail the connect as -ENOTCONN, matching the adjacent setup failures. This keeps XPRT_CONNECTED clear and lets the normal reconnect path retry.

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

xprtrdma: Check frwr_wp_create() during connect

frwr_wp_create() creates the singleton Memory Region used to encode padding for Write chunks whose payload length is not XDR-aligned. Its failure paths return a negative errno and leave ep->re_write_pad_mr set to NULL.

rpcrdma_xprt_connect() currently ignores that return value. If frwr_wp_create() fails after the rest of the connection setup succeeds, xprt_rdma_connect_worker() treats the connection attempt as successful and sets XPRT_CONNECTED. A later NFS/RDMA read with a non-4-byte-aligned receive page length reaches rpcrdma_encode_write_list(), passes the NULL write-pad MR to encode_rdma_segment(), and dereferences it.

This is locally triggerable on an NFS/RDMA client after a connect or reconnect hits a local MR allocation, DMA-map, MR-map, or post-send failure; a remote peer alone cannot force the local MR setup failure.

Check the return value and fail the connect as -ENOTCONN, matching the adjacent setup failures. This keeps XPRT_CONNECTED clear and lets the normal reconnect path retry.

Security update for the Linux Kernel

Security update for the Linux Kernel

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 154 more

In the Linux kernel, the following vulnerability has been resolved: xprtrdma: Check frwr_wp_create() during connect frwr_wp_create() creates the singleton Memory Region used to encode padding for Write chunks whose payload length is not XDR-aligned. Its failure paths return a negative errno and leave ep->re_write_pad_mr set to NULL. rpcrdma_xprt_connect() currently ignores that return value. If frwr_wp_create() fails after the rest of the connection setup succeeds, xprt_rdma_connect_worker() treats the connection attempt as successful and sets XPRT_CONNECTED. A later NFS/RDMA read with a non-4-byte-aligned receive page length reaches rpcrdma_encode_write_list(), passes the NULL write-pad MR to encode_rdma_segment(), and dereferences it. This is locally triggerable on an NFS/RDMA client after a connect or reconnect hits a local MR allocation, DMA-map, MR-map, or post-send failure; a remote peer alone cannot force the local MR setup failure. Check the return value and fail the connect as -ENOTCONN, matching the adjacent setup failures. This keeps XPRT_CONNECTED clear and lets the normal reconnect path retry.

Ein Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um root Rechte zu erlangen, um einen Denial of Service herbeizuführen oder einen nicht näher spezifizierten Angriff durchzuführen.