From: David Windsor <dave@xxxxxxxxxxxx> The autoclose field can be copied with put_user(), so there is no need to use copy_to_user(). In both cases, hardened usercopy is being bypassed since the size is constant, and not open to runtime manipulation. This patch is verbatim from Brad Spengler/PaX Team's PAX_USERCOPY whitelisting code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Signed-off-by: David Windsor <dave@xxxxxxxxxxxx> [kees: adjust commit log] Cc: Vlad Yasevich <vyasevich@xxxxxxxxx> Cc: Neil Horman <nhorman@xxxxxxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: linux-sctp@xxxxxxxxxxxxxxx Cc: netdev@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- net/sctp/socket.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index efbc8f52c531..15491491ec88 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -5011,7 +5011,7 @@ static int sctp_getsockopt_autoclose(struct sock *sk, int len, char __user *optv len = sizeof(int); if (put_user(len, optlen)) return -EFAULT; - if (copy_to_user(optval, &sctp_sk(sk)->autoclose, sizeof(int))) + if (put_user(sctp_sk(sk)->autoclose, (int __user *)optval)) return -EFAULT; return 0; } -- 2.7.4
