linux-kernel - Re: [PATCH v2] eventfs: fix a null pointer access in eventfs

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: <20240903155825.2ec26f1a@gandalf.local.home>
Date: Tue, 3 Sep 2024 15:58:25 -0400
From: Steven Rostedt <rostedt@...dmis.org>
To: Chi Zhiling <chizhiling@....com>
Cc: mhiramat@...nel.org, mathieu.desnoyers@...icios.com,
 linux-trace-kernel@...r.kernel.org, linux-kernel@...r.kernel.org, Chi
 Zhiling <chizhiling@...inos.cn>
Subject: Re: [PATCH v2] eventfs: fix a null pointer access in
 eventfs_iterate

On Thu, 29 Aug 2024 16:50:25 +0800
Chi Zhiling <chizhiling@....com> wrote:

> ---
>  fs/tracefs/event_inode.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
> index 01e99e98457d..18aae67704dc 100644
> --- a/fs/tracefs/event_inode.c
> +++ b/fs/tracefs/event_inode.c
> @@ -642,6 +642,12 @@ static int eventfs_iterate(struct file *file, struct dir_context *ctx)
>  	/* Subtract the skipped entries above */
>  	c -= min((unsigned int)c, (unsigned int)ei->nr_entries);
>  
> +	mutex_lock(&eventfs_mutex);
> +	if (ei->is_freed) {
> +		mutex_unlock(&eventfs_mutex);
> +		goto out;
> +	}
> +
>  	list_for_each_entry_srcu(ei_child, &ei->children, list,
>  				 srcu_read_lock_held(&eventfs_srcu)) {
>  
> @@ -659,9 +665,12 @@ static int eventfs_iterate(struct file *file, struct dir_context *ctx)
>  
>  		ino = eventfs_dir_ino(ei_child);
>  
> -		if (!dir_emit(ctx, name, strlen(name), ino, DT_DIR))
> +		if (!dir_emit(ctx, name, strlen(name), ino, DT_DIR)) {
> +			mutex_unlock(&eventfs_mutex);
>  			goto out_dec;
> +		}
>  	}
> +	mutex_unlock(&eventfs_mutex);
>  	ret = 1;
>   out:
>  	srcu_read_unlock(&eventfs_srcu, idx);
> -- 


Nope, still not correct. See my reply to v1.

Thanks!

-- Steve