linux-kernel - [PATCH net-next 1/4] net: dm: check the boundary of skb drop reasons

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220512062629.10286-2-imagedong@tencent.com>
Date:   Thu, 12 May 2022 14:26:26 +0800
From:   menglong8.dong@...il.com
To:     kuba@...nel.org
Cc:     nhorman@...driver.com, davem@...emloft.net, edumazet@...gle.com,
        pabeni@...hat.com, yoshfuji@...ux-ipv6.org, dsahern@...nel.org,
        imagedong@...cent.com, kafai@...com, talalahmad@...gle.com,
        keescook@...omium.org, asml.silence@...il.com, willemb@...gle.com,
        vasily.averin@...ux.dev, ilias.apalodimas@...aro.org,
        luiz.von.dentz@...el.com, linux-kernel@...r.kernel.org,
        netdev@...r.kernel.org
Subject: [PATCH net-next 1/4] net: dm: check the boundary of skb drop reasons

From: Menglong Dong <imagedong@...cent.com>

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'.

Signed-off-by: Menglong Dong <imagedong@...cent.com>
---
 net/core/drop_monitor.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c
index b89e3e95bffc..020ac5f214d0 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 (reason >= SKB_DROP_REASON_MAX || reason <= 0)
 		reason = SKB_DROP_REASON_NOT_SPECIFIED;
 	cb = NET_DM_SKB_CB(nskb);
 	cb->reason = reason;
-- 
2.36.1