On Mon, 22 Mar 2010 23:31:13 -0400
Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Mon, 22 Mar 2010 15:05:09 +0300 Dan Carpenter <error27@xxxxxxxxx> wrote:
>
> > "m" is never NULL here. We need a different test for the end of list
> > condition.
> >
> > Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
> > ---
> > Found with a static checker and compile tested only. Please review
> > carefully.
> >
> > diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
> > index a44a789..b442dac 100644
> > --- a/fs/proc/kcore.c
> > +++ b/fs/proc/kcore.c
> > @@ -490,7 +490,7 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
> > }
> > read_unlock(&kclist_lock);
> >
> > - if (m == NULL) {
> > + if (&m->list == &kclist_head) {
> > if (clear_user(buffer, tsz))
> > return -EFAULT;
> > } else if (is_vmalloc_or_module_addr((void *)start)) {
>
> hm, that code's been there for five years. I wonder if it's actually necessary.
>
Hmm..on x86 and others, finally,
(kern_addr_valid(start))
will catch bad access. But some architectures seems to define kern_addr_valid() as
#define kern_addr_valid(addr) (1) (from arch/ia64/include/asm/pgtable.h)
Then, we should check "start" is valid address by ourselves (for now). We have
a complete list of registered address in kclist_head.
Regards,
-Kame
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