diff options
| author | Janosch Frank <frankja@linux.ibm.com> | 2018-08-16 09:02:31 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-01 09:44:25 +0100 |
| commit | 2188cf062e566e1d8c350ccafd5f29c9be97e506 (patch) | |
| tree | 97e06cdc1bc64891485effe6f2403da8c375f053 /arch/s390 | |
| parent | a1b53b1b06be2e46f17d6330cc1721d0752042df (diff) | |
s390/mm: Check for valid vma before zapping in gmap_discard
commit 1843abd03250115af6cec0892683e70cf2297c25 upstream.
Userspace could have munmapped the area before doing unmapping from
the gmap. This would leave us with a valid vmaddr, but an invalid vma
from which we would try to zap memory.
Let's check before using the vma.
Fixes: 1e133ab296f3 ("s390/mm: split arch/s390/mm/pgtable.c")
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Message-Id: <20180816082432.78828-1-frankja@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/mm/gmap.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index cb2cd04e6698..b6c85b760305 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -686,6 +686,8 @@ void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to) vmaddr |= gaddr & ~PMD_MASK; /* Find vma in the parent mm */ vma = find_vma(gmap->mm, vmaddr); + if (!vma) + continue; size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK)); zap_page_range(vma, vmaddr, size, NULL); } |