From d9bf5f130946695063469749bfd190087b7fad39 Mon Sep 17 00:00:00 2001 From: Weiping Pan Date: Tue, 13 Aug 2013 21:46:56 +0800 Subject: [PATCH] tun: compare with 0 instead of total_len Since we set "len = total_len" in the beginning of tun_get_user(), so we should compare the new len with 0, instead of total_len, or the if statement always returns false. Signed-off-by: Weiping Pan Signed-off-by: David S. Miller --- drivers/net/tun.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index db690a372260..5a8ee1cf090a 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1074,7 +1074,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, u32 rxhash; if (!(tun->flags & TUN_NO_PI)) { - if ((len -= sizeof(pi)) > total_len) + if ((len -= sizeof(pi)) < 0) return -EINVAL; if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi))) @@ -1083,7 +1083,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, } if (tun->flags & TUN_VNET_HDR) { - if ((len -= tun->vnet_hdr_sz) > total_len) + if ((len -= tun->vnet_hdr_sz) < 0) return -EINVAL; if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso))) -- 2.30.2