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

netfs: Fix netfs_create_write_req() to handle async cache object creation

netfs_create_write_req() will skip caching if the fscache cookie is
disabled, but this is a problem because async cache object creation might
not have got far enough yet that has been enabled - thereby causing the
call to fscache_begin_write_operation() to be skipped.

Fix this by removing the checks on the cookie and delegating this to
fscache_begin_write_operation().