This is a note to let you know that I've just added the patch titled tipc: Use size_add() in calls to struct_size() to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tipc-use-size_add-in-calls-to-struct_size.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 4a26d2ecfec8afa5df7e359a057c400c111336c6 Author: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> Date: Fri Sep 15 13:16:26 2023 -0600 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 <gustavoars@xxxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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; }