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. Additionally, since everything appears to perform a roundup (including allocation), just change the size of the struct itself and add a build-time check to validate the expected size.
Signed-off-by: Kees Cook keescook@chromium.org --- drivers/infiniband/hw/cxgb4/cm.c | 5 +++-- drivers/net/ethernet/chelsio/cxgb4/t4_msg.h | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c index 291471d12197..7129ae025b2d 100644 --- a/drivers/infiniband/hw/cxgb4/cm.c +++ b/drivers/infiniband/hw/cxgb4/cm.c @@ -2471,7 +2471,8 @@ static int accept_cr(struct c4iw_ep *ep, struct sk_buff *skb, skb_get(skb); rpl = cplhdr(skb); if (!is_t4(adapter_type)) { - skb_trim(skb, roundup(sizeof(*rpl5), 16)); + BUILD_BUG_ON(sizeof(*rpl5) != roundup(sizeof(*rpl5), 16)); + skb_trim(skb, sizeof(*rpl5)); rpl5 = (void *)rpl; INIT_TP_WR(rpl5, ep->hwtid); } else { @@ -2487,7 +2488,7 @@ static int accept_cr(struct c4iw_ep *ep, struct sk_buff *skb, opt2 |= CONG_CNTRL_V(CONG_ALG_TAHOE); opt2 |= T5_ISS_F; rpl5 = (void *)rpl; - memset(&rpl5->iss, 0, roundup(sizeof(*rpl5)-sizeof(*rpl), 16)); + memset_after(rpl5, 0, opt0); if (peer2peer) isn += 4; rpl5->iss = cpu_to_be32(isn); diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_msg.h b/drivers/net/ethernet/chelsio/cxgb4/t4_msg.h index fed5f93bf620..26433a62d7f0 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/t4_msg.h +++ b/drivers/net/ethernet/chelsio/cxgb4/t4_msg.h @@ -497,7 +497,7 @@ struct cpl_t5_pass_accept_rpl { __be32 opt2; __be64 opt0; __be32 iss; - __be32 rsvd; + __be32 rsvd[3]; };
struct cpl_act_open_req {