From 8096090858689395a75bbf696ff8276c3c236b98 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 25 Feb 2016 12:15:48 -0800 Subject: [PATCH] AIO: properly check iovec sizes commit ff19ac8fb71e8a2bf07d61b959062998139c1104 upstream 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. Bug: 28588279 Reported-by: Ben Hawkes Acked-by: Benjamin LaHaise Tested-by: Willy Tarreau [backported to 3.10 - willy] Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman Change-Id: If539a08b42dd51a473b3f3743f9497e637266a05 --- fs/aio.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/aio.c b/fs/aio.c index ded94c4fa30d3..9798d4edfd8f2 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -977,12 +977,17 @@ static ssize_t aio_setup_vectored_rw(int rw, struct kiocb *kiocb, bool compat) 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; }