linux-kernel - Re: [PATCH] tipc: fix a potential deadlock on &tx->lock

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: <0ce8658b-9b8a-923c-a5bd-c63284d2db96@intel.com>
Date:   Fri, 29 Sep 2023 11:29:50 -0700
From:   Jacob Keller <jacob.e.keller@...el.com>
To:     Chengfeng Ye <dg573847474@...il.com>, <jmaloy@...hat.com>,
        <ying.xue@...driver.com>, <davem@...emloft.net>,
        <edumazet@...gle.com>, <kuba@...nel.org>, <pabeni@...hat.com>
CC:     <netdev@...r.kernel.org>, <tipc-discussion@...ts.sourceforge.net>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] tipc: fix a potential deadlock on &tx->lock



On 9/27/2023 11:14 AM, Chengfeng Ye wrote:
> It seems that tipc_crypto_key_revoke() could be be invoked by
> wokequeue tipc_crypto_work_rx() under process context and
> timer/rx callback under softirq context, thus the lock acquisition
> on &tx->lock seems better use spin_lock_bh() to prevent possible
> deadlock.
> 
> This flaw was found by an experimental static analysis tool I am
> developing for irq-related deadlock.
> 

Interesting.

> tipc_crypto_work_rx() <workqueue>
> --> tipc_crypto_key_distr()
> --> tipc_bcast_xmit()
> --> tipc_bcbase_xmit()
> --> tipc_bearer_bc_xmit()
> --> tipc_crypto_xmit()
> --> tipc_ehdr_build()
> --> tipc_crypto_key_revoke()
> --> spin_lock(&tx->lock)
> <timer interrupt>
>    --> tipc_disc_timeout()
>    --> tipc_bearer_xmit_skb()
>    --> tipc_crypto_xmit()
>    --> tipc_ehdr_build()
>    --> tipc_crypto_key_revoke()
>    --> spin_lock(&tx->lock) <deadlock here>
> 
> Signed-off-by: Chengfeng Ye <dg573847474@...il.com>
> ---

Reviewed-by: Jacob Keller <jacob.e.keller@...el.com>

>  net/tipc/crypto.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c
> index 302fd749c424..43c3f1c971b8 100644
> --- a/net/tipc/crypto.c
> +++ b/net/tipc/crypto.c
> @@ -1441,14 +1441,14 @@ static int tipc_crypto_key_revoke(struct net *net, u8 tx_key)
>  	struct tipc_crypto *tx = tipc_net(net)->crypto_tx;
>  	struct tipc_key key;
>  
> -	spin_lock(&tx->lock);
> +	spin_lock_bh(&tx->lock);
>  	key = tx->key;
>  	WARN_ON(!key.active || tx_key != key.active);
>  
>  	/* Free the active key */
>  	tipc_crypto_key_set_state(tx, key.passive, 0, key.pending);
>  	tipc_crypto_key_detach(tx->aead[key.active], &tx->lock);
> -	spin_unlock(&tx->lock);
> +	spin_unlock_bh(&tx->lock);
>  
>  	pr_warn("%s: key is revoked\n", tx->name);
>  	return -EKEYREVOKED;