| Message ID | 20210909162248.14969-7-david@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390: fixes, cleanups and optimizations for page table walkers | expand |
On Thu, 9 Sep 2021 18:22:45 +0200 David Hildenbrand <david@redhat.com> wrote: > 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: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") > Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> > --- > arch/s390/pci/pci_mmio.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c > index ae683aa623ac..c5b35ea129cf 100644 > --- a/arch/s390/pci/pci_mmio.c > +++ b/arch/s390/pci/pci_mmio.c > @@ -159,7 +159,7 @@ SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned > long, mmio_addr, > mmap_read_lock(current->mm); > ret = -EINVAL; > - vma = find_vma(current->mm, mmio_addr); > + vma = vma_lookup(current->mm, mmio_addr); > if (!vma) > goto out_unlock_mmap; > if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) > @@ -298,7 +298,7 @@ SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned > long, mmio_addr, > mmap_read_lock(current->mm); > ret = -EINVAL; > - vma = find_vma(current->mm, mmio_addr); > + vma = vma_lookup(current->mm, mmio_addr); > if (!vma) > goto out_unlock_mmap; > if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> * David Hildenbrand <david@redhat.com> [210909 12:24]: > 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: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") > Signed-off-by: David Hildenbrand <david@redhat.com> > --- > arch/s390/pci/pci_mmio.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c > index ae683aa623ac..c5b35ea129cf 100644 > --- a/arch/s390/pci/pci_mmio.c > +++ b/arch/s390/pci/pci_mmio.c > @@ -159,7 +159,7 @@ SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr, > > mmap_read_lock(current->mm); > ret = -EINVAL; > - vma = find_vma(current->mm, mmio_addr); > + vma = vma_lookup(current->mm, mmio_addr); > if (!vma) > goto out_unlock_mmap; > if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) > @@ -298,7 +298,7 @@ SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr, > > mmap_read_lock(current->mm); > ret = -EINVAL; > - vma = find_vma(current->mm, mmio_addr); > + vma = vma_lookup(current->mm, mmio_addr); > if (!vma) > goto out_unlock_mmap; > if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) > -- > 2.31.1 > >
diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c index ae683aa623ac..c5b35ea129cf 100644 --- a/arch/s390/pci/pci_mmio.c +++ b/arch/s390/pci/pci_mmio.c @@ -159,7 +159,7 @@ SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr, mmap_read_lock(current->mm); ret = -EINVAL; - vma = find_vma(current->mm, mmio_addr); + vma = vma_lookup(current->mm, mmio_addr); if (!vma) goto out_unlock_mmap; if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) @@ -298,7 +298,7 @@ SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr, mmap_read_lock(current->mm); ret = -EINVAL; - vma = find_vma(current->mm, mmio_addr); + vma = vma_lookup(current->mm, mmio_addr); if (!vma) goto out_unlock_mmap; if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
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: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") Signed-off-by: David Hildenbrand <david@redhat.com> --- arch/s390/pci/pci_mmio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)