| Message ID | 20210909145945.12192-6-david@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | s390: fixes, cleanups and optimizations for page table walkers | expand |
* David Hildenbrand <david@redhat.com> [210909 11:01]: > We should not walk/touch page tables outside of VMA boundaries when > holding only the mmap sem in read mode. Evil user space can modify the > VMA layout just before this function runs and e.g., trigger races with > page table removal code since commit dd2283f2605e ("mm: mmap: zap pages > with read mmap_sem in munmap"). > > find_vma() does not check if the address is >= the VMA start address; > use vma_lookup() instead. > > Fixes: 214d9bbcd3a6 ("s390/mm: provide memory management functions for protected KVM guests") > Signed-off-by: David Hildenbrand <david@redhat.com> > --- > arch/s390/kernel/uv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c > index aeb0a15bcbb7..193205fb2777 100644 > --- a/arch/s390/kernel/uv.c > +++ b/arch/s390/kernel/uv.c > @@ -227,7 +227,7 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb) > uaddr = __gmap_translate(gmap, gaddr); > if (IS_ERR_VALUE(uaddr)) > goto out; > - vma = find_vma(gmap->mm, uaddr); > + vma = vma_lookup(gmap->mm, uaddr); > if (!vma) > goto out; > /* > -- > 2.31.1 > > Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c index aeb0a15bcbb7..193205fb2777 100644 --- a/arch/s390/kernel/uv.c +++ b/arch/s390/kernel/uv.c @@ -227,7 +227,7 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb) uaddr = __gmap_translate(gmap, gaddr); if (IS_ERR_VALUE(uaddr)) goto out; - vma = find_vma(gmap->mm, uaddr); + vma = vma_lookup(gmap->mm, uaddr); if (!vma) goto out; /*
We should not walk/touch page tables outside of VMA boundaries when holding only the mmap sem in read mode. Evil user space can modify the VMA layout just before this function runs and e.g., trigger races with page table removal code since commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap"). find_vma() does not check if the address is >= the VMA start address; use vma_lookup() instead. Fixes: 214d9bbcd3a6 ("s390/mm: provide memory management functions for protected KVM guests") Signed-off-by: David Hildenbrand <david@redhat.com> --- arch/s390/kernel/uv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)