Re: [PATCH] kernfs: fix off by one error.

[ebiederm@xmission.com (Eric W. Biederman)]

Richard Cochran <richardcochran@gmail.com> writes:

> The hash values 0 and 1 are reserved for magic directory entries, but
> the code only prevents names hashing to 0. This patch fixes the test
> to also prevent hash value 1.
>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
> Signed-off-by: Richard Cochran <richardcochran@gmail.com>
> Cc: <stable@vger.kernel.org>
> ---
>  fs/kernfs/dir.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
> index bd6e18b..39c0143 100644
> --- a/fs/kernfs/dir.c
> +++ b/fs/kernfs/dir.c
> @@ -37,7 +37,7 @@ static unsigned int kernfs_name_hash(const char *name, const void *ns)
>  	hash = (end_name_hash(hash) ^ hash_ptr((void *)ns, 31));
>  	hash &= 0x7fffffffU;
>  	/* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */
> -	if (hash < 1)
> +	if (hash < 2)
>  		hash += 2;
>  	if (hash >= INT_MAX)
>  		hash = INT_MAX - 1;