In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memset(), avoid intentionally writing across neighboring fields.
Use memset_after() so memset() doesn't get confused about writing beyond the destination member that is intended to be the starting point of zeroing through the end of the struct.
Signed-off-by: Kees Cook keescook@chromium.org --- drivers/infiniband/hw/mthca/mthca_mr.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/infiniband/hw/mthca/mthca_mr.c b/drivers/infiniband/hw/mthca/mthca_mr.c index ce0e0867e488..64adba5c067d 100644 --- a/drivers/infiniband/hw/mthca/mthca_mr.c +++ b/drivers/infiniband/hw/mthca/mthca_mr.c @@ -469,8 +469,7 @@ int mthca_mr_alloc(struct mthca_dev *dev, u32 pd, int buffer_size_shift, mpt_entry->start = cpu_to_be64(iova); mpt_entry->length = cpu_to_be64(total_size);
- memset(&mpt_entry->lkey, 0, - sizeof *mpt_entry - offsetof(struct mthca_mpt_entry, lkey)); + memset_after(mpt_entry, 0, length);
if (mr->mtt) mpt_entry->mtt_seg =