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authorAndrey Konovalov <andreyknvl@google.com>2017-03-29 16:11:20 +0200
committerBen Hutchings <ben@decadent.org.uk>2017-06-05 21:17:21 +0100
commita481ab4edd87bc2dc6f1fa9029866dd69c86fc5c (patch)
treee25fffa8561f0fb5001f4e6e420c4cace533fd01
parent629655f798b92fd309fdde494a3cfb8a37f807ad (diff)
net/packet: fix overflow in check for priv area size
commit 2b6867c2ce76c596676bec7d2d525af525fdc6e2 upstream. Subtracting tp_sizeof_priv from tp_block_size and casting to int to check whether one is less then the other doesn't always work (both of them are unsigned ints). Compare them as is instead. Also cast tp_sizeof_priv to u64 before using BLK_PLUS_PRIV, as it can overflow inside BLK_PLUS_PRIV otherwise. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--net/packet/af_packet.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 193eac992814..a56a8d059bd1 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3842,8 +3842,8 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
goto out;
if (po->tp_version >= TPACKET_V3 &&
- (int)(req->tp_block_size -
- BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
+ req->tp_block_size <=
+ BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv))
goto out;
if (unlikely(req->tp_frame_size < po->tp_hdrlen +
po->tp_reserve))