Commit a3af33ab authored by Menglong Dong's avatar Menglong Dong Committed by David S. Miller
Browse files

net: dm: check the boundary of skb drop reasons 



The 'reason' will be set to 'SKB_DROP_REASON_NOT_SPECIFIED' if it not
small that SKB_DROP_REASON_MAX in net_dm_packet_trace_kfree_skb_hit(),
but it can't avoid it to be 0, which is invalid and can cause NULL
pointer in drop_reasons.

Therefore, reset it to SKB_DROP_REASON_NOT_SPECIFIED when 'reason <= 0'.

Reviewed-by: default avatarJiang Biao <benbjiang@tencent.com>
Reviewed-by: default avatarHao Peng <flyingpeng@tencent.com>
Signed-off-by: default avatarMenglong Dong <imagedong@tencent.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3aba1030

net/core/drop_monitor.c

+1 −1
Original line number Diff line number Diff line
@@ -517,7 +517,7 @@ static void net_dm_packet_trace_kfree_skb_hit(void *ignore, 
	if (!nskb)

		return;



	if ((unsigned int)reason >= SKB_DROP_REASON_MAX)

	if (unlikely(reason >= SKB_DROP_REASON_MAX || reason <= 0))

		reason = SKB_DROP_REASON_NOT_SPECIFIED;

	cb = NET_DM_SKB_CB(nskb);

	cb->reason = reason;