userfaultfd: fix a race between writeprotect and exit_mmap()
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.2%
exploitation probability
0.2%top 94% of all CVEs
observed exploitation
nono source reports it
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.
Affected products
Linux · Linux