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authorDan Carpenter <dan.carpenter@oracle.com>2013-08-15 15:52:57 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-09-14 06:54:55 -0700
commitb59bde78dbf049a2671603034562940ac6eb1181 (patch)
tree07d3336bcbd649b3781828deafc232df46fe9806
parentf784dbb9b9b868185b78295b120dbc1f79513e55 (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>
-rw-r--r--drivers/net/tun.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 2491eb28a8d..7b54f4f052d 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1076,8 +1076,9 @@ 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)) > total_len)
+ if (len < sizeof(pi))
return -EINVAL;
+ len -= sizeof(pi);
if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
return -EFAULT;
@@ -1085,8 +1086,9 @@ 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) > total_len)
+ if (len < tun->vnet_hdr_sz)
return -EINVAL;
+ len -= tun->vnet_hdr_sz;
if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
return -EFAULT;