This is a note to let you know that I've just added the patch titled
net/packet: check length in getsockopt() called with PACKET_HDRLEN
to the 3.18-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:
net-packet-check-length-in-getsockopt-called-with-packet_hdrlen.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Oct 5 10:58:04 CEST 2017
From: Alexander Potapenko <glider@xxxxxxxxxx>
Date: Tue, 25 Apr 2017 18:51:46 +0200
Subject: net/packet: check length in getsockopt() called with PACKET_HDRLEN
From: Alexander Potapenko <glider@xxxxxxxxxx>
[ Upstream commit fd2c83b35752f0a8236b976978ad4658df14a59f ]
In the case getsockopt() is called with PACKET_HDRLEN and optlen < 4
|val| remains uninitialized and the syscall may behave differently
depending on its value, and even copy garbage to userspace on certain
architectures. To fix this we now return -EINVAL if optlen is too small.
This bug has been detected with KMSAN.
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/packet/af_packet.c | 2 ++
1 file changed, 2 insertions(+)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3482,6 +3482,8 @@ static int packet_getsockopt(struct sock
case PACKET_HDRLEN:
if (len > sizeof(int))
len = sizeof(int);
+ if (len < sizeof(int))
+ return -EINVAL;
if (copy_from_user(&val, optval, len))
return -EFAULT;
switch (val) {
Patches currently in stable-queue which might be from glider@xxxxxxxxxx are
queue-3.18/net-packet-check-length-in-getsockopt-called-with-packet_hdrlen.patch