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authorColy Li <colyli@suse.de>2020-10-02 16:27:31 +0800
committerDavid S. Miller <davem@davemloft.net>2020-10-02 15:27:08 -0700
commitcf83a17edeeb36195596d2dae060a7c381db35f1 (patch)
treebd90a7efe648a0b8c2d75ca0a1dcaa4d6b89610d /net
parent7d4194abfc4de13a2663c7fee6891de8360f7a52 (diff)
downloadlinux-cf83a17edeeb36195596d2dae060a7c381db35f1.tar.bz2
tcp: use sendpage_ok() to detect misused .sendpage
commit a10674bf2406 ("tcp: detecting the misuse of .sendpage for Slab objects") adds the checks for Slab pages, but the pages don't have page_count are still missing from the check. Network layer's sendpage method is not designed to send page_count 0 pages neither, therefore both PageSlab() and page_count() should be both checked for the sending page. This is exactly what sendpage_ok() does. This patch uses sendpage_ok() in do_tcp_sendpages() to detect misused .sendpage, to make the code more robust. Fixes: a10674bf2406 ("tcp: detecting the misuse of .sendpage for Slab objects") Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Coly Li <colyli@suse.de> Cc: Vasily Averin <vvs@virtuozzo.com> Cc: David S. Miller <davem@davemloft.net> Cc: stable@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 31f3b858db81..2135ee7c806d 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -970,7 +970,8 @@ ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
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"))
+ WARN_ONCE(!sendpage_ok(page),
+ "page must not be a Slab one and have page_count > 0"))
return -EINVAL;
/* Wait for a connection to finish. One exception is TCP Fast Open