On Fri, Aug 26, 2022 at 12:24:54PM +0200, Christophe JAILLET wrote:
> If this memdup_user() call fails, the memory allocated in a previous call
> a few lines above should be freed. Otherwise it leaks.
>
> Fixes: 6ee95d1c8991 ("nfsd: add support for upcall version 2")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> Speculative, untested.
> ---
> fs/nfsd/nfs4recover.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
> index b29d27eaa8a6..248ff9f4141c 100644
> --- a/fs/nfsd/nfs4recover.c
> +++ b/fs/nfsd/nfs4recover.c
> @@ -815,8 +815,10 @@ __cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
> princhash.data = memdup_user(
> &ci->cc_princhash.cp_data,
> princhashlen);
> - if (IS_ERR_OR_NULL(princhash.data))
> + if (IS_ERR_OR_NULL(princhash.data)) {
> + kfree(name.data);
> return -EFAULT;
This comment is not directed at you and is not related to your patch.
But memdup_user() never returns NULL, only error pointers. I wrote a
fifteen page blog entry about NULL vs error pointers the other week.
https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/
This should propagate the error code from memdup_user() instead of
-EFAULT.
regards,
dan carpenter
