Messages in this thread | | | From | BlaisorBlade <> | Subject | Re: [PATCH/2.4.26] Avoid kernel data corruption through /dev/kmem | Date | Sat, 3 Jul 2004 20:13:45 +0200 |
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Alle 15:18, venerdì 2 luglio 2004, Marcelo Tosatti ha scritto: > On Thu, Jul 01, 2004 at 04:05:29PM +0200, BlaisorBlade wrote:
> This looks much better for inclusion. But do you actually have a problem > with write to /dev/kmem not returning correct error code? The *other* time I spoke about error code... but it seems you don't have noticed the part *below* of my mail, the one where I describe what I complain about kernel memory corruption... read below:
> If you convince me there are good enough reasons we can try this on > 2.4.28-pre.
> > We need to check if do_write_mem == -EFAULT. > > In fact, without that check, we could execute this: > > > > do_write_mem returns -EFAULT; > > wrote = -EFAULT; > > > > buf += wrote; //i.e. buf -= EFAULT (14); > > > > ... read other data from buf, and write it to kernel memory And those datas are crap, obviously: the app wanted to write *buf to kernel memory, not *(buf-14), so we can have data corruption.
> > (actually on special circumstances, i.e. p < high_memory && > > p + count > high_memory).
-- Paolo Giarrusso, aka Blaisorblade Linux registered user n. 292729
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