CVE-2025-21655

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux21a091b970cdbcf3e8ff829234b51be6f9192766 < 6b63308c28987c6010b1180c72a6db4df6c68033affected
LinuxLinux21a091b970cdbcf3e8ff829234b51be6f9192766 < 8efff2aa2d95dc437ab67c5b4a9f1d3f367baa10affected
LinuxLinux21a091b970cdbcf3e8ff829234b51be6f9192766 < a7085c3ae43b86d4b3d1b8275e6a67f14257e3b7affected
LinuxLinux21a091b970cdbcf3e8ff829234b51be6f9192766 < c9a40292a44e78f71258b8522655bffaf5753bdbaffected
LinuxLinux6.1affected
LinuxLinux0 < 6.1unaffected
LinuxLinux6.1.125 <= 6.1.*unaffected
LinuxLinux6.6.72 <= 6.6.*unaffected
LinuxLinux6.12.10 <= 6.12.*unaffected
LinuxLinux6.13 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

References