From 95aef86ab231f047bb8085c70666059b58f53c09 Mon Sep 17 00:00:00 2001 From: Stefan Wiehler Date: Tue, 28 Oct 2025 17:12:27 +0100 Subject: [PATCH] sctp: Prevent TOCTOU out-of-bounds write For the following path not holding the sock lock, sctp_diag_dump() -> sctp_for_each_endpoint() -> sctp_ep_dump() make sure not to exceed bounds in case the address list has grown between buffer allocation (time-of-check) and write (time-of-use). Suggested-by: Kuniyuki Iwashima Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file") Signed-off-by: Stefan Wiehler Reviewed-by: Kuniyuki Iwashima Acked-by: Xin Long Link: https://patch.msgid.link/20251028161506.3294376-3-stefan.wiehler@nokia.com Signed-off-by: Jakub Kicinski --- net/sctp/diag.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/sctp/diag.c b/net/sctp/diag.c index 1a8761f87bf1..5d64dd99ca9a 100644 --- a/net/sctp/diag.c +++ b/net/sctp/diag.c @@ -88,6 +88,9 @@ static int inet_diag_msg_sctpladdrs_fill(struct sk_buff *skb, memcpy(info, &laddr->a, sizeof(laddr->a)); memset(info + sizeof(laddr->a), 0, addrlen - sizeof(laddr->a)); info += addrlen; + + if (!--addrcnt) + break; } rcu_read_unlock(); -- 2.47.3