Patch "AIO: properly check iovec sizes" has been added to the 3.10-stable tree

Patch "AIO: properly check iovec sizes" has been added to the 3.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    AIO: properly check iovec sizes

to the 3.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     aio-properly-check-iovec-sizes.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From greg@kroah.com Fri Feb 19 17:36:28 2016
From: Greg KH <greg@kroah.com>
Date: Fri, 19 Feb 2016 17:36:21 -0800
Subject: AIO: properly check iovec sizes

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In Linus's tree, the iovec code has been reworked massively, but in
older kernels the AIO layer should be checking this before passing the
request on to other layers.

Many thanks to Ben Hawkes of Google Project Zero for pointing out the
issue.

Reported-by: Ben Hawkes <hawkes@google.com>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Tested-by: Willy Tarreau <w@1wt.eu>
[backported to 3.10 - willy]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 fs/aio.c |   11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

--- a/fs/aio.c
+++ b/fs/aio.c
@@ -977,12 +977,17 @@ static ssize_t aio_setup_vectored_rw(int
 
 static ssize_t aio_setup_single_vector(int rw, struct kiocb *kiocb)
 {
-	if (unlikely(!access_ok(!rw, kiocb->ki_buf, kiocb->ki_nbytes)))
-		return -EFAULT;
+	size_t len = kiocb->ki_nbytes;
+
+	if (len > MAX_RW_COUNT)
+		len = MAX_RW_COUNT;
+
+	if (unlikely(!access_ok(!rw, kiocb->ki_buf, len)))
+                return -EFAULT;
 
 	kiocb->ki_iovec = &kiocb->ki_inline_vec;
 	kiocb->ki_iovec->iov_base = kiocb->ki_buf;
-	kiocb->ki_iovec->iov_len = kiocb->ki_nbytes;
+	kiocb->ki_iovec->iov_len = len;
 	kiocb->ki_nr_segs = 1;
 	return 0;
 }


Patches currently in stable-queue which might be from greg@kroah.com are

queue-3.10/mm-memory_hotplug.c-check-for-missing-sections-in-test_pages_in_a_zone.patch
queue-3.10/aio-properly-check-iovec-sizes.patch