From: Dan Carpenter <dan.carpenter@oracle•com>
To: "David S. Miller" <davem@davemloft•net>
Cc: Jason Wang <jasowang@redhat•com>,
"Michael S. Tsirkin" <mst@redhat•com>,
Eric Dumazet <edumazet@google•com>,
Neil Horman <nhorman@tuxdriver•com>,
netdev@vger•kernel.org, kernel-janitors@vger•kernel.org
Subject: [patch] tun: signedness bug in tun_get_user()
Date: Thu, 15 Aug 2013 15:52:57 +0300 [thread overview]
Message-ID: <20130815125257.GA16932@elgon.mountain> (raw)
The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is
not totally correct. Because "len" and "sizeof()" are size_t type, that
means they are never less than zero.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle•com>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index af987f0..7ed13cc 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -977,8 +977,9 @@ 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)) < 0)
+ if (len < sizeof(pi))
return -EINVAL;
+ len -= sizeof(pi);
if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
return -EFAULT;
@@ -986,8 +987,9 @@ 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) < 0)
+ if (len < tun->vnet_hdr_sz)
return -EINVAL;
+ len -= tun->vnet_hdr_sz;
if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
return -EFAULT;
next reply other threads:[~2013-08-15 12:53 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-15 12:52 Dan Carpenter [this message]
2013-08-15 14:04 ` [patch] tun: signedness bug in tun_get_user() Michael S. Tsirkin
2013-08-15 14:58 ` Michael S. Tsirkin
2013-08-15 15:02 ` Michael S. Tsirkin
2013-08-15 15:05 ` Michael S. Tsirkin
2013-08-15 20:08 ` Neil Horman
2013-08-15 21:51 ` David Miller
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