From 254187a64a3043b5b20b6efc4a7e139a88bff6ae Mon Sep 17 00:00:00 2001 From: Gustavo A. R. Silva Date: Fri, 15 Sep 2023 13:16:26 -0600 Subject: tipc: Use size_add() in calls to struct_size() [ Upstream commit 2506a91734754de690869824fb0d1ac592ec1266 ] If, for any reason, the open-coded arithmetic causes a wraparound, the protection that `struct_size()` adds against potential integer overflows is defeated. Fix this by hardening call to `struct_size()` with `size_add()`. Fixes: e034c6d23bc4 ("tipc: Use struct_size() helper") Signed-off-by: Gustavo A. R. Silva Reviewed-by: Kees Cook Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/tipc/link.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/tipc/link.c b/net/tipc/link.c index 2eff1c7949cb..8715c9b05f90 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -1446,7 +1446,7 @@ u16 tipc_get_gap_ack_blks(struct tipc_gap_ack_blks **ga, struct tipc_link *l, p = (struct tipc_gap_ack_blks *)msg_data(hdr); sz = ntohs(p->len); /* Sanity check */ - if (sz == struct_size(p, gacks, p->ugack_cnt + p->bgack_cnt)) { + if (sz == struct_size(p, gacks, size_add(p->ugack_cnt, p->bgack_cnt))) { /* Good, check if the desired type exists */ if ((uc && p->ugack_cnt) || (!uc && p->bgack_cnt)) goto ok; @@ -1533,7 +1533,7 @@ static u16 tipc_build_gap_ack_blks(struct tipc_link *l, struct tipc_msg *hdr) __tipc_build_gap_ack_blks(ga, l, ga->bgack_cnt) : 0; /* Total len */ - len = struct_size(ga, gacks, ga->bgack_cnt + ga->ugack_cnt); + len = struct_size(ga, gacks, size_add(ga->bgack_cnt, ga->ugack_cnt)); ga->len = htons(len); return len; } -- cgit v1.2.3