Re: [PATCH] fs: kernfs: fix possible null pointer dereferences

From: Greg Kroah-Hartman
Date: Wed May 06 2020 - 08:44:11 EST


On Thu, Apr 30, 2020 at 04:20:46AM -0700, youngjun wrote:
> kernfs_path_from_node_locked checks buf is NULL.
> But, two cases below are not covered.
>
> if(!kn_to) <--- case1 (buf can be NULL)
> return strlcpy(buf, "(null)", buflen);
>
> if(kn_from == kn_to) <--- case2 (buf can be NULL)
> return strlcpy(buf, "/", buflen);
>
> if (!buf) <--- checked here.
> return -EINVAL;
>
> buf NULL case needs to be checked first.
>
> Signed-off-by: youngjun <her0gyugyu@xxxxxxxxx>
> ---
> fs/kernfs/dir.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)

I have 3 patches here from you, with the same subject lines, yet they do
different things.

I'm dropping them all, can you please resend a patch series of the
remaining patches you wish us to review for kernfs?

thanks,

greg k-h