5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
[ 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 <gustavoars@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/tipc/link.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/tipc/link.c b/net/tipc/link.c
index dbb1bc722ba9b..5f849c7300283 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1410,7 +1410,7 @@ 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;
@@ -1497,7 +1497,7 @@ 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;
}
--
2.42.0
