Re: CVE-2022-50455: nfs: fix possible null-ptr-deref when parsing param

Re: CVE-2022-50455: nfs: fix possible null-ptr-deref when parsing param

[Wang Zhaolong]

> From: Greg Kroah-Hartman <gregkh@kernel.org>
> 
> Description
> ===========
> 
> In the Linux kernel, the following vulnerability has been resolved:
> 
> nfs: fix possible null-ptr-deref when parsing param
> 
> According to commit "vfs: parse: deal with zero length string value",
> kernel will set the param->string to null pointer in vfs_parse_fs_string()
> if fs string has zero length.
> 

Hi Greg,

The patch "vfs: parse: deal with zero length string value", which introduced
this issue, was never merged into mainline.

It only exists in the mailing list:
https://lists.openwall.net/linux-kernel/2022/06/28/18

Since the problematic behavior never existed in any released kernel,
CVE-2022-50455 cannot be valid.

Please consider rejecting this CVE.

Best regards,
Wang Zhaolong

Re: CVE-2022-50455: nfs: fix possible null-ptr-deref when parsing param

[Greg Kroah-Hartman]

On Fri, Oct 10, 2025 at 10:19:40AM +0800, Wang Zhaolong wrote:
> 
> 
> 
> 
> > From: Greg Kroah-Hartman <gregkh@kernel.org>
> > 
> > Description
> > ===========
> > 
> > In the Linux kernel, the following vulnerability has been resolved:
> > 
> > nfs: fix possible null-ptr-deref when parsing param
> > 
> > According to commit "vfs: parse: deal with zero length string value",
> > kernel will set the param->string to null pointer in vfs_parse_fs_string()
> > if fs string has zero length.
> > 
> 
> Hi Greg,
> 
> The patch "vfs: parse: deal with zero length string value", which introduced
> this issue, was never merged into mainline.
> 
> It only exists in the mailing list:
> https://lists.openwall.net/linux-kernel/2022/06/28/18

Please always use lore.kernel.org for emails, I had to go dig out the
whole thread from there based on that to determine what happened here :(

> Since the problematic behavior never existed in any released kernel,
> CVE-2022-50455 cannot be valid.
> 
> Please consider rejecting this CVE.

Makes sense, I'll go reject this now, thanks for the review!

greg k-h