From: Kees Cook Date: Mon, 13 Dec 2021 22:33:28 +0000 (-0800) Subject: IB/mthca: Use memset_startat() for clearing mpt_entry X-Git-Tag: v5.17-rc1~89^2~32 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=59aa7fcfe2e44afbe9736e5cfa941699021d6957;p=thirdparty%2Fkernel%2Flinux.git IB/mthca: Use memset_startat() for clearing mpt_entry In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memset(), avoid intentionally writing across neighboring fields. Use memset_startat() 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. Link: https://lore.kernel.org/r/20211213223331.135412-15-keescook@chromium.org Signed-off-by: Kees Cook Signed-off-by: Jason Gunthorpe --- diff --git a/drivers/infiniband/hw/mthca/mthca_mr.c b/drivers/infiniband/hw/mthca/mthca_mr.c index a59100c496b44..192f83fd7c8a5 100644 --- a/drivers/infiniband/hw/mthca/mthca_mr.c +++ b/drivers/infiniband/hw/mthca/mthca_mr.c @@ -467,8 +467,7 @@ 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_startat(mpt_entry, 0, lkey); if (mr->mtt) mpt_entry->mtt_seg =