On Fri, Jan 24, 2020 at 12:52:18PM +0000, Anton Ivanov wrote:
>
>
> On 24/01/2020 10:14, Dan Carpenter wrote:
> > 1) The uml_vector_user_bpf() returns pointers so it should return NULL
> > instead of false.
> > 2) If the "bpf_prog" allocation failed, it would have eventually lead to
> > a crash. We can't succeed after the error happens so it should just
> > return.
> >
> > Fixes: 9807019a62dc ("um: Loadable BPF "Firmware" for vector drivers")
> > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > ---
> > arch/um/drivers/vector_user.c | 10 +++++-----
> > 1 file changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
> > index ddcd917be0af..88483f5b034c 100644
> > --- a/arch/um/drivers/vector_user.c
> > +++ b/arch/um/drivers/vector_user.c
> > @@ -732,13 +732,13 @@ void *uml_vector_user_bpf(char *filename)
> > if (stat(filename, &statbuf) < 0) {
> > printk(KERN_ERR "Error %d reading bpf file", -errno);
> > - return false;
> > + return NULL;
>
> I will sort this one out, thanks for noticing.
>
> > }
> > bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL);
> > - if (bpf_prog != NULL) {
> > - bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter);
> > - bpf_prog->filter = NULL;
> > - }
> > + if (!pfg_prog)
>
> ^^^^^ ?
If we don't return here it leads to a NULL dereference.
regards,
dan carpenter
