linux-kernel - Re: [PATCH] ecryptfs: fix kernel panic with null dev

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: <20210419055148.GC405651@elm>
Date:   Mon, 19 Apr 2021 00:51:48 -0500
From:   Tyler Hicks <code@...icks.com>
To:     Jeffrey Mitchell <jeffrey.mitchell@...rlab.io>
Cc:     ecryptfs@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ecryptfs: fix kernel panic with null dev_name

On 2021-02-26 15:00:23, Jeffrey Mitchell wrote:
> When mounting eCryptfs, a null "dev_name" argument to ecryptfs_mount()
> causes a kernel panic if the parsed options are valid. The easiest way to
> reproduce this is to call mount() from userspace with an existing
> eCryptfs mount's options and a "source" argument of 0.
> 
> Error out if "dev_name" is null in ecryptfs_mount()
> 
> Signed-off-by: Jeffrey Mitchell <jeffrey.mitchell@...rlab.io>

Thanks for the fix! I reproduced this on a 4.15 and, while I didn't try
anything older than that, I think it affects the first kernel release
with eCryptfs. I've added the following Fixes tag:

 Fixes: 237fead61998 ("[PATCH] ecryptfs: fs/Makefile and fs/Kconfig")

I've pushed it to the next branch of tyhicks/ecryptfs.git.

Tyler

> ---
>  fs/ecryptfs/main.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
> index e63259fdef28..b2f6a1937d23 100644
> --- a/fs/ecryptfs/main.c
> +++ b/fs/ecryptfs/main.c
> @@ -492,6 +492,12 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
>  		goto out;
>  	}
>  
> +	if (!dev_name) {
> +		rc = -EINVAL;
> +		err = "Device name cannot be null";
> +		goto out;
> +	}
> +
>  	rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid);
>  	if (rc) {
>  		err = "Error parsing options";
> -- 
> 2.25.1
>