[PATCH net] sctp: Prevent TOCTOU out-of-bounds write

From: Stefan Wiehler

Date: Mon Oct 27 2025 - 05:06:31 EST


Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file")
Signed-off-by: Stefan Wiehler <stefan.wiehler@xxxxxxxxx>
---
net/sctp/diag.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/net/sctp/diag.c b/net/sctp/diag.c
index 996c2018f0e6..4ee44e0111ae 100644
--- a/net/sctp/diag.c
+++ b/net/sctp/diag.c
@@ -85,6 +85,9 @@ 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;
}

return 0;
--
2.51.0