4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Rodrigo Rivas Costa <rodrigorivascosta@xxxxxxxxx>
commit a955358d54695e4ad9f7d6489a7ac4d69a8fc711 upstream.
Doing `ioctl(HIDIOCGFEATURE)` in a tight loop on a hidraw device
and then disconnecting the device, or unloading the driver, can
cause a NULL pointer dereference.
When a hidraw device is destroyed it sets 0 to `dev->exist`.
Most functions check 'dev->exist' before doing its work, but
`hidraw_get_report()` was missing that check.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Rodrigo Rivas Costa <rodrigorivascosta@xxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/hid/hidraw.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -192,6 +192,11 @@ static ssize_t hidraw_get_report(struct
int ret = 0, len;
unsigned char report_number;
+ if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
+ ret = -ENODEV;
+ goto out;
+ }
+
dev = hidraw_table[minor]->hid;
if (!dev->ll_driver->raw_request) {