diff options
| author | Dan Carpenter <dan.carpenter@oracle.com> | 2013-08-15 15:52:57 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-09-14 06:02:09 -0700 |
| commit | 62d5a1d2a8a7c247c1f2dcd87b1e8c533b03017b (patch) | |
| tree | f74aa6e80308a50e4ac97e8db8df1f67060265ae /drivers/net/tun.c | |
| parent | abdf975d2095b3f41939ec0e2259af5d485f2889 (diff) | |
tun: signedness bug in tun_get_user()
[ Upstream commit 15718ea0d844e4816dbd95d57a8a0e3e264ba90e ]
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>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net/tun.c')
| -rw-r--r-- | drivers/net/tun.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index c896b8f5f03..194f8798b7e 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -615,8 +615,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, int offset = 0; if (!(tun->flags & TUN_NO_PI)) { - if ((len -= sizeof(pi)) > count) + if (len < sizeof(pi)) return -EINVAL; + len -= sizeof(pi); if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi))) return -EFAULT; @@ -624,8 +625,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, } if (tun->flags & TUN_VNET_HDR) { - if ((len -= tun->vnet_hdr_sz) > count) + if (len < tun->vnet_hdr_sz) return -EINVAL; + len -= tun->vnet_hdr_sz; if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso))) return -EFAULT; |