On Tue, Jun 19, 2018 at 05:57:35PM -0700, Alistair Strachan wrote: > The ashmem driver did not check that the size/offset of the vma passed > to its .mmap() function was not larger than the ashmem object being > mapped. This could cause mmap() to succeed, even though accessing parts > of the mapping would later fail with a segmentation fault. > > Ensure an error is returned by the ashmem_mmap() function if the vma > size is larger than the ashmem object size. This enables safer handling > of the problem in userspace. > > Cc: Greg Kroah-Hartman <[email protected]> > Cc: Arve Hjønnevåg <[email protected]> > Cc: Todd Kjos <[email protected]> > Cc: Martijn Coenen <[email protected]> > Cc: [email protected] > Cc: [email protected] > Cc: [email protected] > Cc: Joel Fernandes <[email protected]> > Signed-off-by: Alistair Strachan <[email protected]> > --- > v2: Removed unnecessary use of unlikely() macro > > drivers/staging/android/ashmem.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/staging/android/ashmem.c > b/drivers/staging/android/ashmem.c > index c6386e4f5c9b..e392358ec244 100644 > --- a/drivers/staging/android/ashmem.c > +++ b/drivers/staging/android/ashmem.c > @@ -366,6 +366,12 @@ static int ashmem_mmap(struct file *file, struct > vm_area_struct *vma) > goto out; > } > > + /* requested mapping size larger than object size */ > + if (vma->vm_end - vma->vm_start > PAGE_ALIGN(asma->size)) { > + ret = -EINVAL; > + goto out; > + } > +
Acked-by: Joel Fernandes (Google) <[email protected]> thanks, - Joel _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
