[41/64] net: dccp: Use memset_after() for TP zeroing

Message ID 20210727205855.411487-42-keescook@chromium.org
State Superseded
Headers show
Series
  • Introduce strict memcpy() bounds checking
Related show

Commit Message

Kees Cook July 27, 2021, 8:58 p.m.
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>
---
 net/dccp/trace.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

Patch

diff --git a/net/dccp/trace.h b/net/dccp/trace.h
index 5062421beee9..3c2594da49fc 100644
--- a/net/dccp/trace.h
+++ b/net/dccp/trace.h
@@ -60,9 +60,7 @@  TRACE_EVENT(dccp_probe,
 			__entry->tx_t_ipi = hc->tx_t_ipi;
 		} else {
 			__entry->tx_s = 0;
-			memset(&__entry->tx_rtt, 0, (void *)&__entry->tx_t_ipi -
-			       (void *)&__entry->tx_rtt +
-			       sizeof(__entry->tx_t_ipi));
+			memset_after(__entry, 0, tx_s);
 		}
 	),