RDMA/rxe: Fix incomplete state save in rxe_requester
CVE: CVE-2023-53539
Component: kernel
Severity: Moderate
CVSS v3: 7.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Release date: 2023-01-01T00:00:00+00:00

An incorrect state restoration flaw was found in the Linux kernel's RDMA rxe (soft-RoCE) driver in the requester packet transmission logic. 
A local user with access to RDMA devices can trigger this issue when network layer packet drops occur during RDMA send operations, causing the work queue element state to be incompletely saved and restored. This results in data corruption in resent packets, leading to denial of service or potential data integrity issues.

Statement: The vulnerability occurs when rxe_requester attempts to retransmit a packet after receiving -EAGAIN from the IP layer. The code saves work queue element state to enable retransmission, but fails to preserve the DMA structure that tracks scatter-gather list processing. Additionally, the state snapshot happens after packet construction has already modified the DMA fields. When heavy network stress causes packet drops—particularly when a fast sender communicates with a slow receiver across multiple queue pairs—the incomplete restoration causes retransmitted packets to carry corrupted payload data.

Remediation:
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.
For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.
To mitigate this issue, prevent the rdma_rxe module from being loaded. See https://access.redhat.com/solutions/41278 for instructions on blacklisting kernel modules.