Early Access — Mondoo Vulnerability Intelligence is currently in preview.
In the Linux kernel, the following vulnerability has been resolved:
userfaultfd: fix a race between writeprotect and exit_mmap()
A race is possible when a process exits, its VMAs are removed by exit_mmap() and at the same time userfaultfd_writeprotect() is called.
The race was detected by KASAN on a development kernel, but it appears to be possible on vanilla kernels as well.
Use mmget_not_zero() to prevent the race as done in other userfaultfd operations.