CVE-2025-37920 xsk: Fix race condition in AF_XDP generic RX path
A race condition in the Linux kernel's AF_XDP generic RX path allows concurrent access issues, potentially leading to system instability or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-37920?
CVE-2025-37920 is a high-severity vulnerability in Linux kernel, published on 20 May 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-362
Which versions are affected by CVE-2025-37920?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-37920?
Apply the vendor's patch.
Is CVE-2025-37920 being exploited?
There is no known exploitation of CVE-2025-37920 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-62598, AZL-69941, BELL-CVE-2025-37920, DEBIAN-CVE-2025-37920, GHSA-4qc6-52f6-6vgr, ROOT-OS-DEBIAN-11-CVE-2025-37920 and 4 more.