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authorArnd Bergmann <arnd@arndb.de>2020-01-08 11:00:00 +0100
committerMauro Carvalho Chehab <mchehab+huawei@kernel.org>2020-01-08 13:27:58 +0100
commit1dc8b65c944e5cfce3d830a5b97b42be185a1984 (patch)
treeef39a9c754f0f74fc9efab6e598b52dbe1b44945 /drivers/media
parente4b9b6454d94481483c435b94517249b79e82b63 (diff)
media: v4l2-core: only zero-out ioctl-read buffers
The memset() got moved out of the check for _IOC_NONE, so passing a made-up command number with a size but no direction would allow clearing data on user-provided pointers. Move video_get_user() back into the _IOC_NONE check where it belongs. Reported-by: syzbot+54fd8cca4b7226c94b8e@syzkaller.appspotmail.com Fixes: 6c625c01c7a6 ("media: v4l2-core: split out data copy from video_usercopy") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/v4l2-core/v4l2-ioctl.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index b68ff06009cd..aaf83e254272 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -3205,12 +3205,12 @@ video_usercopy(struct file *file, unsigned int orig_cmd, unsigned long arg,
parg = mbuf;
}
+ err = video_get_user((void __user *)arg, parg, orig_cmd,
+ &always_copy);
+ if (err)
+ goto out;
}
- err = video_get_user((void __user *)arg, parg, orig_cmd, &always_copy);
- if (err)
- goto out;
-
err = check_array_args(cmd, parg, &array_size, &user_ptr, &kernel_ptr);
if (err < 0)
goto out;