CVE-2025-37920

Description

From CVE.org

In the Linux kernel, the following vulnerability has been resolved: xsk: Fix race condition in AF_XDP generic RX path Move rx_lock from xsk_socket to xsk_buff_pool. Fix synchronization for shared umem mode in generic RX path where multiple sockets share single xsk_buff_pool. RX queue is exclusive to xsk_socket, while FILL queue can be shared between multiple sockets. This could result in race condition where two CPU cores access RX path of two different sockets sharing the same umem. Protect both queues by acquiring spinlock in shared xsk_buff_pool. Lock contention may be minimized in the future by some per-thread FQ buffering. It's safe and necessary to move spin_lock_bh(rx_lock) after xsk_rcv_check(): * xs->pool and spinlock_init is synchronized by xsk_bind() -> xsk_is_bound() memory barriers. * xsk_rcv_check() may return true at the moment of xsk_release() or xsk_unbind_dev(), however this will not cause any data races or race conditions. xsk_unbind_dev() removes xdp socket from all maps and waits for completion of all outstanding rx operations. Packets in RX path will either complete safely or drop.

Statement

A race condition in the AF_XDP generic receive path allowed two CPU cores to concurrently access the same xsk_buff_pool via different sockets sharing the same UMEM. This patch moves the rx_lock to the shared buffer pool to properly synchronize access and prevent data corruption or memory consistency bugs in shared receive paths.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score4.14.77.8
Attack VectorLocalLocalLocal
Attack ComplexityHighHighLow
Privileges RequiredHighLowLow
User InteractionNoneNoneNone
ScopeUnchangedUnchangedUnchanged
ConfidentialityNoneNoneHigh
Integrity ImpactNoneNoneHigh
Availability ImpactHighHighHigh

Vector

Red Hat: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H

NVD: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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