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authorAndrey Konovalov2017-03-29 16:11:20 +0200
committerDavid S. Miller2017-03-30 11:03:59 -0700
commit2b6867c2ce76c596676bec7d2d525af525fdc6e2 (patch)
tree3388a523680f25b180c48280cc224d374c2fdd37
parent8f1f7eeb22c16a197159cf7b35d1350695193ead (diff)
net/packet: fix overflow in check for priv area size
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>
-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 a0dbe7ca8f72..2323ee35dc09 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -4193,8 +4193,8 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
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))