From a6f8ee58a8e35f7e4380a5efce312e2a5bc27497 Mon Sep 17 00:00:00 2001 From: Arjun Roy Date: Thu, 6 May 2021 15:35:30 -0700 Subject: tcp: Specify cmsgbuf is user pointer for receive zerocopy. A prior change (1f466e1f15cf) introduces separate handling for ->msg_control depending on whether the pointer is a kernel or user pointer. However, while tcp receive zerocopy is using this field, it is not properly annotating that the buffer in this case is a user pointer. This can cause faults when the improper mechanism is used within put_cmsg(). This patch simply annotates tcp receive zerocopy's use as explicitly being a user pointer. Fixes: 7eeba1706eba ("tcp: Add receive timestamp support for receive zerocopy.") Signed-off-by: Arjun Roy Acked-by: Soheil Hassas Yeganeh Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20210506223530.2266456-1-arjunroy.kdev@gmail.com Signed-off-by: Jakub Kicinski --- net/ipv4/tcp.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/ipv4') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index e14fd0c50c10..f1c1f9e3de72 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2039,6 +2039,7 @@ static void tcp_zc_finalize_rx_tstamp(struct sock *sk, (__kernel_size_t)zc->msg_controllen; cmsg_dummy.msg_flags = in_compat_syscall() ? MSG_CMSG_COMPAT : 0; + cmsg_dummy.msg_control_is_user = true; zc->msg_flags = 0; if (zc->msg_control == msg_control_addr && zc->msg_controllen == cmsg_dummy.msg_controllen) { -- cgit v1.2.3-58-ga151