Messages in this thread | | | Subject | Re: [PATCH 5/6] nfs: check all iov segments for correct memory access rights | From | Badari Pulavarty <> | Date | Fri, 19 May 2006 11:25:06 -0700 |
| |
On Fri, 2006-05-19 at 14:00 -0400, Chuck Lever wrote:
> > +/* > + * Check: > + * 1. All bytes in the user buffers are properly accessible > + * 2. The resulting number of bytes won't overflow ssize_t > + */ > +static ssize_t check_access_ok(int type, const struct iovec *iov, unsigned long nr_segs) > +{ > + ssize_t count = 0; > + ssize_t retval = -EINVAL; > + unsigned long seg; > + > + for (seg = 0; seg < nr_segs; seg++) { > + void __user *buf = iov[seg].iov_base; > + ssize_t len = (ssize_t) iov[seg].iov_len; > + > + if (len < 0) /* size_t not fitting an ssize_t .. */ > + goto out; > + if (unlikely(!access_ok(type, buf, len))) { > + retval = -EFAULT; > + goto out; > + } > + count += len; > + if (count < 0) /* math overflow on the ssize_t */ > + goto out; > + } > + retval = count; > +out: > + return retval; > +} > +
May be move this to fs/read_write.c and export it - since we do the same thing there also ?
Thanks, Badari
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |