linux-kernel - Re: [PATCH] configfs: fix a race in configfs

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] [day] [month] [year] [list]

Message-ID: <2023090222-rover-gilled-22d2@gregkh>
Date:   Sat, 2 Sep 2023 08:45:31 +0200
From:   Greg KH <gregkh@...uxfoundation.org>
To:     Kyle Zeng <zengyhkyle@...il.com>
Cc:     jlbec@...lplan.org, hch@....de, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] configfs: fix a race in configfs_lookup() in
 stable-5.10.y

On Fri, Sep 01, 2023 at 05:50:37PM -0700, Kyle Zeng wrote:
> Basically porting c42dd069be8dfc9b2239a5c89e73bbd08ab35de0 to
> stable-v5.10.y to avoid race condition between configfs_dir_lseek and
> configfs_lookup since they both operate ->s_childre and configfs_lookup
> forgets to obtain the lock.
> 
> Signed-off-by: Kyle Zeng <zengyhkyle@...il.com>
> ---
>  fs/configfs/dir.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
> index 12388ed4faa5..0b7e9ab517d5 100644
> --- a/fs/configfs/dir.c
> +++ b/fs/configfs/dir.c
> @@ -479,6 +479,7 @@ static struct dentry * configfs_lookup(struct inode *dir,
>  	if (!configfs_dirent_is_ready(parent_sd))
>  		goto out;
>  
> +	spin_lock(&configfs_dirent_lock);
>  	list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
>  		if (sd->s_type & CONFIGFS_NOT_PINNED) {
>  			const unsigned char * name = configfs_get_name(sd);
> @@ -491,6 +492,7 @@ static struct dentry * configfs_lookup(struct inode *dir,
>  			break;
>  		}
>  	}
> +	spin_unlock(&configfs_dirent_lock);
>  
>  	if (!found) {
>  		/*
> -- 
> 2.34.1
> 

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>