| Message ID | ZQStiorAZPgfMMZD@work (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [next] tipc: Use size_add() in calls to struct_size() | expand |
On Fri, Sep 15, 2023 at 01:16:26PM -0600, Gustavo A. R. Silva wrote: > 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@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org>
diff --git a/net/tipc/link.c b/net/tipc/link.c index e33b4f29f77c..d0143823658d 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; }
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@kernel.org> --- net/tipc/link.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)