CVE-2026-98388

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

exec: do close on exec() before taking exec update lock

do close on exec() currently happens while holding the exec update lock, which is used in a lot of places that access process state to synchronize access checks. I recently added another such use of exec update lock, causing a regression.

do close on exec() can block waiting for a reply from a filesystem. That means a hung filesystem can block codepaths that use exec update lock; and it also means that a FUSE filesystem which attempts to inspect the calling process can deadlock.

To avoid such problems, move do close on exec() before the exec update lock is taken, but after the FD table has been copied if necessary.

I have looked through all the calls between the old and new position of the do close on exec() call; there seems to be no file descriptor table access in between.