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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2013-08-15 15:52:57 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-08-15 14:51:23 -0700 |
| commit | 15718ea0d844e4816dbd95d57a8a0e3e264ba90e (patch) | |
| tree | 1cd9c06a746d5e7173bfbe07ed84058c47ec4736 /drivers/net | |
| parent | d1fcc172570fa4de69c60bdabe1e1ccfcfe80c26 (diff) | |
| download | linux-15718ea0d844e4816dbd95d57a8a0e3e264ba90e.tar.gz linux-15718ea0d844e4816dbd95d57a8a0e3e264ba90e.tar.bz2 linux-15718ea0d844e4816dbd95d57a8a0e3e264ba90e.zip | |
tun: signedness bug in tun_get_user()
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>
Diffstat (limited to 'drivers/net')
| -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 5a8ee1cf090a..71af122edf2d 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1074,8 +1074,9 @@ 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; @@ -1083,8 +1084,9 @@ 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; |