xfs: check for valid indices in xfs_iext_get_ext and xfs_iext_idx_to_irec
xfs: check for valid indices in xfs_iext_get_ext and xfs_iext_idx_to_irec

Based on an earlier patch from Lachlan McIlroy.

Signed-off-by: Christoph Hellwig <923f7720577207a44b32e59bbfbea59d27f1ae8e@lst.de>
Reviewed-by: Lachlan McIlroy <ff9e869555c1bbba9d4ec165450acb53740323ed@redhat.com>
Signed-off-by: Alex Elder <f556392d917047d964350b9c68912016c96d5e94@sgi.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs