sctp: Prevent TOCTOU out-of-bounds write

[ Upstream commit 95aef86ab2 ]

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 <kuniyu@google.com>
Fixes: 8f840e47f1 ("sctp: add the sctp_diag.c file")
Signed-off-by: Stefan Wiehler <stefan.wiehler@nokia.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20251028161506.3294376-3-stefan.wiehler@nokia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Stefan Wiehler
2025-10-28 17:12:27 +01:00
committed by Greg Kroah-Hartman
parent 97a2bb90a6
commit 2fe08fcaac

View File

@@ -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();