Re: [PATCH][2/2] ide-tape: small cleanups - handle copy_to|from_user()failures

[Jesper Juhl]

On Sun, 28 Nov 2004, Alan Cox wrote:

> On Sul, 2004-11-28 at 16:32, Jesper Juhl wrote:
> >  #endif /* IDETAPE_DEBUG_BUGS */
> >  		count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), (unsigned int)n);
> > -		copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count);
> > +		if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count))
> > +			return -EFAULT;
> >  		n -= count;
> >  		atomic_add(count, &bh->b_count);
> >  		buf += count;
> 
> If you do this then you don't fix up tape->bh for further operations.

True, if copy_from_user fails it just bails out, I didn't see anything 
really bad that could happen from that, but I'm an idiot, looking at it 
again I guess it could probably mess up tape->bh pretty bad.
Guess I need to go back and look at this in greater detail.
Thank you for looking at it.

> Have you tested these changes including the I/O errors ?
> 
As I noted in the [0/2] mail I don't have hardware to test these patches, 
so they need to be reviewed.


--
Jesper Juhl


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/