Bug 2516720 (CVE-2026-72467)

Summary: CVE-2026-72467 kernel: xprtrdma: Check frwr_wp_create() during connect
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's xprtrdma module. The system fails to properly check the return value of frwr_wp_create(), which is responsible for creating a Memory Region. If this creation fails, a subsequent Network File System (NFS) over Remote Direct Memory Access (RDMA) read operation with an unaligned receive page length can lead to a NULL pointer dereference. This can result in a system crash, causing a denial of service, and is locally triggerable on an NFS/RDMA client.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-08-15 06:27:39 UTC 
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.
Comment 1 Keith Grant 2026-08-19 17:44:24 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081534-CVE-2026-72467-cca8@gregkh/T