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| author | Luke Nowakowski-Krijger <lnowakow@eng.ucsd.edu> | 2019-07-17 10:19:46 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-05 12:27:44 +0200 |
| commit | 84a6dd572b18177bc66dd90b4a865eb3f8c0a1c0 (patch) | |
| tree | e6db741cb615cfb5689a3f2680f9d6471ed9fd0e | |
| parent | 78335bc692d72f54348e95ee62e1942401faf995 (diff) | |
| download | linux-stable-84a6dd572b18177bc66dd90b4a865eb3f8c0a1c0.tar.gz linux-stable-84a6dd572b18177bc66dd90b4a865eb3f8c0a1c0.tar.bz2 linux-stable-84a6dd572b18177bc66dd90b4a865eb3f8c0a1c0.zip | |
media: hdpvr: Add device num check and handling
[ Upstream commit d4a6a9537bc32811486282206ecfb7c53754b74d ]
Add hdpvr device num check and error handling
We need to increment the device count atomically before we checkout a
device to make sure that we do not reach the max count, otherwise we get
out-of-bounds errors as reported by syzbot.
Reported-and-tested-by: syzbot+aac8d0d7205f112045d2@syzkaller.appspotmail.com
Signed-off-by: Luke Nowakowski-Krijger <lnowakow@eng.ucsd.edu>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/media/usb/hdpvr/hdpvr-core.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/media/usb/hdpvr/hdpvr-core.c b/drivers/media/usb/hdpvr/hdpvr-core.c index 08f0ca7aa012..924517b09fc9 100644 --- a/drivers/media/usb/hdpvr/hdpvr-core.c +++ b/drivers/media/usb/hdpvr/hdpvr-core.c @@ -278,6 +278,7 @@ static int hdpvr_probe(struct usb_interface *interface, #endif size_t buffer_size; int i; + int dev_num; int retval = -ENOMEM; /* allocate memory for our device state and initialize it */ @@ -386,8 +387,17 @@ static int hdpvr_probe(struct usb_interface *interface, } #endif + dev_num = atomic_inc_return(&dev_nr); + if (dev_num >= HDPVR_MAX) { + v4l2_err(&dev->v4l2_dev, + "max device number reached, device register failed\n"); + atomic_dec(&dev_nr); + retval = -ENODEV; + goto reg_fail; + } + retval = hdpvr_register_videodev(dev, &interface->dev, - video_nr[atomic_inc_return(&dev_nr)]); + video_nr[dev_num]); if (retval < 0) { v4l2_err(&dev->v4l2_dev, "registering videodev failed\n"); goto reg_fail; |