From 9c7ba1d7634cef490b85bc64c4091ff004821bfd Mon Sep 17 00:00:00 2001 From: Daniel Mentz Date: Wed, 2 Aug 2017 23:42:17 -0400 Subject: [PATCH] media: v4l2-compat-ioctl32: Fix timespec conversion 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: stable@vger.kernel.org Cc: H. Peter Anvin Cc: Laurent Pinchart Cc: Tiffany Lin Cc: Ricardo Ribalda Delgado Cc: Sakari Ailus Signed-off-by: Daniel Mentz Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index 84ad195562c7..af8b4c5b0efa 100644 --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -799,7 +799,8 @@ static int put_v4l2_event32(struct v4l2_event *kp, struct v4l2_event32 __user *u 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;