This is a note to let you know that I've just added the patch titled
media: v4l2-compat-ioctl32: Fix timespec conversion
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:
media-v4l2-compat-ioctl32-fix-timespec-conversion.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 9c7ba1d7634cef490b85bc64c4091ff004821bfd Mon Sep 17 00:00:00 2001
From: Daniel Mentz <danielmentz@xxxxxxxxxx>
Date: Wed, 2 Aug 2017 23:42:17 -0400
Subject: media: v4l2-compat-ioctl32: Fix timespec conversion
From: Daniel Mentz <danielmentz@xxxxxxxxxx>
commit 9c7ba1d7634cef490b85bc64c4091ff004821bfd upstream.
Certain syscalls like recvmmsg support 64 bit timespec values for the
X32 ABI. The helper function compat_put_timespec converts a timespec
value to a 32 bit or 64 bit value depending on what ABI is used. The
v4l2 compat layer, however, is not designed to support 64 bit timespec
values and always uses 32 bit values. Hence, compat_put_timespec must
not be used.
Without this patch, user space will be provided with bad timestamp
values from the VIDIOC_DQEVENT ioctl. Also, fields of the struct
v4l2_event32 that come immediately after timestamp get overwritten,
namely the field named id.
Fixes: 81993e81a994 ("compat: Get rid of (get|put)_compat_time(val|spec)")
Cc: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
Cc: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
Cc: Tiffany Lin <tiffany.lin@xxxxxxxxxxxx>
Cc: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Signed-off-by: Daniel Mentz <danielmentz@xxxxxxxxxx>
Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -747,7 +747,8 @@ static int put_v4l2_event32(struct v4l2_
copy_to_user(&up->u, &kp->u, sizeof(kp->u)) ||
put_user(kp->pending, &up->pending) ||
put_user(kp->sequence, &up->sequence) ||
- compat_put_timespec(&kp->timestamp, &up->timestamp) ||
+ put_user(kp->timestamp.tv_sec, &up->timestamp.tv_sec) ||
+ put_user(kp->timestamp.tv_nsec, &up->timestamp.tv_nsec) ||
put_user(kp->id, &up->id) ||
copy_to_user(up->reserved, kp->reserved, 8 * sizeof(__u32)))
return -EFAULT;
Patches currently in stable-queue which might be from danielmentz@xxxxxxxxxx are
queue-3.18/media-v4l2-compat-ioctl32-fix-timespec-conversion.patch