splice: missing user pointer access verification

vmsplice_to_user() must always check the user pointer and length
with access_ok() before copying. Likewise, for the slow path of
copy_from_user_mmap_sem() we need to check that we may read from
the user region.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Wojciech Purczynski <cliph@research.coseinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jens Axboe 2008-02-08 08:49:14 -08:00 committed by Linus Torvalds
parent 66191dc622
commit 8811930dc7

View file

@ -1179,6 +1179,9 @@ static int copy_from_user_mmap_sem(void *dst, const void __user *src, size_t n)
{
int partial;
if (!access_ok(VERIFY_READ, src, n))
return -EFAULT;
pagefault_disable();
partial = __copy_from_user_inatomic(dst, src, n);
pagefault_enable();
@ -1387,6 +1390,11 @@ static long vmsplice_to_user(struct file *file, const struct iovec __user *iov,
break;
}
if (unlikely(!access_ok(VERIFY_WRITE, base, len))) {
error = -EFAULT;
break;
}
sd.len = 0;
sd.total_len = len;
sd.flags = flags;