5.10-stable review patch. If anyone has any objections, please let me know.
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From: Gustavo A. R. Silva gustavoars@kernel.org
[ 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@kernel.org Reviewed-by: Kees Cook keescook@chromium.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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; }