From a10674bf2406afc2554f9c7d31b2dc65d6a27fd9 Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Wed, 6 Mar 2019 14:10:22 +0300 Subject: tcp: detecting the misuse of .sendpage for Slab objects sendpage was not designed for processing of the Slab pages, in some situations it can trigger BUG_ON on receiving side. Signed-off-by: Vasily Averin Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index ad07dd71063d..dbb08140cdc9 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -943,6 +943,10 @@ ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, ssize_t copied; long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); + if (IS_ENABLED(CONFIG_DEBUG_VM) && + WARN_ONCE(PageSlab(page), "page must not be a Slab one")) + return -EINVAL; + /* Wait for a connection to finish. One exception is TCP Fast Open * (passive side) where data is allowed to be sent before a connection * is fully established. -- cgit v1.2.3-59-g8ed1b