CVE-2025-21655 Affecting linux-6.1 package, versions <6.1.128-1~deb11u1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.05% (19th percentile)

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  • Snyk IDSNYK-DEBIAN11-LINUX61-9055604
  • published3 Mar 2025
  • disclosed20 Jan 2025

Introduced: 20 Jan 2025

CVE-2025-21655  (opens in a new tab)

How to fix?

Upgrade Debian:11 linux-6.1 to version 6.1.128-1~deb11u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-6.1 package and not the linux-6.1 package as distributed by Debian. See How to fix? for Debian:11 relevant fixed versions and status.

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

io_uring/eventfd: ensure io_eventfd_signal() defers another RCU period

io_eventfd_do_signal() is invoked from an RCU callback, but when dropping the reference to the io_ev_fd, it calls io_eventfd_free() directly if the refcount drops to zero. This isn't correct, as any potential freeing of the io_ev_fd should be deferred another RCU grace period.

Just call io_eventfd_put() rather than open-code the dec-and-test and free, which will correctly defer it another RCU grace period.

CVSS Base Scores

version 3.1