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From: Tyler Hicks <tyhicks@canonical.com>
To: Dan Carpenter <dan.carpenter@oracle.com>,
	Michael Halcrow <mhalcrow@us.ibm.com>
Cc: ecryptfs@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] eCryptfs: use after free in ecryptfs_release_messaging()
Date: Fri, 13 Oct 2017 21:24:09 -0400	[thread overview]
Message-ID: <2e7b4c48-aea4-0951-1010-33380b2e6b73@canonical.com> (raw)
In-Reply-To: <20170822204128.7xhtrlpvueucbisl@mwanda>


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Hi Dan - Thanks for the patch. I'm sorry for not getting back to you
until now.

On 08/22/2017 04:41 PM, Dan Carpenter wrote:
> We're freeing the list iterator so we should be using the _safe()
> version of hlist_for_each_entry().
> 
> Fixes: 88b4a07e6610 ("[PATCH] eCryptfs: Public key transport mechanism")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

I think this patch is correct. I'll perform some testing and, if all
goes well, get it in before 4.14 is released.

Tyler

> ---
> It's also possible that I misunderstood this code.  Please review with
> caution.
> 
> diff --git a/fs/ecryptfs/messaging.c b/fs/ecryptfs/messaging.c
> index 286f10b0363b..4f457d5c4933 100644
> --- a/fs/ecryptfs/messaging.c
> +++ b/fs/ecryptfs/messaging.c
> @@ -442,15 +442,16 @@ void ecryptfs_release_messaging(void)
>  	}
>  	if (ecryptfs_daemon_hash) {
>  		struct ecryptfs_daemon *daemon;
> +		struct hlist_node *n;
>  		int i;
>  
>  		mutex_lock(&ecryptfs_daemon_hash_mux);
>  		for (i = 0; i < (1 << ecryptfs_hash_bits); i++) {
>  			int rc;
>  
> -			hlist_for_each_entry(daemon,
> -					     &ecryptfs_daemon_hash[i],
> -					     euid_chain) {
> +			hlist_for_each_entry_safe(daemon, n,
> +						  &ecryptfs_daemon_hash[i],
> +						  euid_chain) {
>  				rc = ecryptfs_exorcise_daemon(daemon);
>  				if (rc)
>  					printk(KERN_ERR "%s: Error whilst "
> --
> To unsubscribe from this list: send the line "unsubscribe ecryptfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 



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      reply	other threads:[~2017-10-14  1:24 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-22 20:41 [PATCH] eCryptfs: use after free in ecryptfs_release_messaging() Dan Carpenter
2017-10-14  1:24 ` Tyler Hicks [this message]

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