HID: prodikeys: Fix general protection fault during probe
The syzbot fuzzer provoked a general protection fault in the
hid-prodikeys driver:
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.3.0-rc5+ #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
RIP: 0010:pcmidi_submit_output_report drivers/hid/hid-prodikeys.c:300 [inline]
RIP: 0010:pcmidi_set_operational drivers/hid/hid-prodikeys.c:558 [inline]
RIP: 0010:pcmidi_snd_initialise drivers/hid/hid-prodikeys.c:686 [inline]
RIP: 0010:pk_probe+0xb51/0xfd0 drivers/hid/hid-prodikeys.c:836
Code: 0f 85 50 04 00 00 48 8b 04 24 4c 89 7d 10 48 8b 58 08 e8 b2 53 e4 fc
48 8b 54 24 20 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f
85 13 04 00 00 48 ba 00 00 00 00 00 fc ff df 49 8b
The problem is caused by the fact that pcmidi_get_output_report() will
return an error if the HID device doesn't provide the right sort of
output report, but pcmidi_set_operational() doesn't bother to check
the return code and assumes the function call always succeeds.
This patch adds the missing check and aborts the probe operation if
necessary.