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| author |  Luke Nowakowski-Krijger <lnowakow@eng.ucsd.edu>
| 2019-07-17 10:19:46 -0400 |
|---|---|---|
| committer |  Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
| 2019-07-25 06:23:35 -0400 |
| commit | d4a6a9537bc32811486282206ecfb7c53754b74d (patch) | |
| tree | 922d20b5ed372ec8759cff83c7eaf9ae2ff92151 /drivers/media/usb | |
| parent | media: staging: media: cedrus: Fix misuse of GENMASK macro (diff) | |
| download | linux-d4a6a9537bc32811486282206ecfb7c53754b74d.tar.gz linux-d4a6a9537bc32811486282206ecfb7c53754b74d.tar.bz2 linux-d4a6a9537bc32811486282206ecfb7c53754b74d.zip | |
media: hdpvr: Add device num check and handling
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>
Diffstat (limited to 'drivers/media/usb')
| -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 9b9d894d29bc..a0905c81d2cb 100644 --- a/drivers/media/usb/hdpvr/hdpvr-core.c +++ b/drivers/media/usb/hdpvr/hdpvr-core.c @@ -271,6 +271,7 @@ 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 */ @@ -368,8 +369,17 @@ 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; |