s390/uaccess: Prevent kprobes on cmpxchg_user_key() functions

Browse source

Code regions within cmpxchg_user_key() functions may be executed with a
non-default access key, which may lead to a protection exception if the
corresponding page has the fetch-protection bit enabled.

There is code in place which initializes the storage keys of such pages
when needed. However there is also the possibility of out-of-line execution
of such code in case a kprobe is set within such a region.

To avoid this problem prevent that any kprobe can be set within the
cmpxchg_user_key() functions.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

...

This commit is contained in:

Heiko Carstens 2025-06-16 17:00:32 +02:00 • committed by Alexander Gordeev

parent b13c190c6d

commit d2b73ce90a

1 changed files with 11 additions and 10 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

21

arch/s390/lib/uaccess.c

View file