On Tue, Aug 30, 2022 at 09:11:54PM +0000, Chuck Lever III wrote:
>
>
> > On Aug 26, 2022, at 7:08 AM, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
> >
> > 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.
>
> I take it then that Christophe should redrive this with your suggested
> corrections? I haven't applied this yet because I was waiting for
> follow-up.
No, that's a different thing. If anyone wants to clean that up then it
should be part of a different patch.
regards,
dan carpenter
