RE: [PATCH v2] net: tipc: fix possible infoleak in tipc_mon_rcv()

[Tung Quang Nguyen]

> -----Original Message-----
> From: Hangyu Hua <hbh25y@xxxxxxxxx>
> Sent: Tuesday, June 28, 2022 3:31 PM
> To: jmaloy@xxxxxxxxxx; ying.xue@xxxxxxxxxxxxx; davem@xxxxxxxxxxxxx; edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx;
> pabeni@xxxxxxxxxx; Tung Quang Nguyen <tung.q.nguyen@xxxxxxxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx; tipc-discussion@xxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Hangyu Hua <hbh25y@xxxxxxxxx>
> Subject: [PATCH v2] net: tipc: fix possible infoleak in tipc_mon_rcv()
> 
> dom_bef is use to cache current domain record only if current domain
> exists. But when current domain does not exist, dom_bef will still be used
> in mon_identify_lost_members. This may lead to an information leak.
> 
> Fix this by adding a memset before using dom_bef.
> 
> Fixes: 35c55c9877f8 ("tipc: add neighbor monitoring framework")
> Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx>
> ---
> 
> v2: remove redundant 'dom_bef.member_cnt = 0;'
> 
>  net/tipc/monitor.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/tipc/monitor.c b/net/tipc/monitor.c
> index 2f4d23238a7e..03b5d0b65169 100644
> --- a/net/tipc/monitor.c
> +++ b/net/tipc/monitor.c
> @@ -534,7 +534,7 @@ void tipc_mon_rcv(struct net *net, void *data, u16 dlen, u32 addr,
>  	state->peer_gen = new_gen;
> 
>  	/* Cache current domain record for later use */
> -	dom_bef.member_cnt = 0;
> +	memset(&dom_bef, 0, sizeof(dom_bef));
>  	dom = peer->domain;
>  	if (dom)
>  		memcpy(&dom_bef, dom, dom->len);
> --
> 2.25.1
Reviewed-by: Tung Nguyen <tung.q.nguyen@xxxxxxxxxxxxxx>