From a3af33abd9210c93dc829b4fdd7a19f63f168a25 Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Fri, 13 May 2022 11:03:36 +0800 Subject: 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: Jiang Biao Reviewed-by: Hao Peng Signed-off-by: Menglong Dong Signed-off-by: David S. Miller --- net/core/drop_monitor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/core') diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index b89e3e95bffc..41cac0e4834e 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -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; -- cgit v1.2.3