diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2019-09-04 11:54:20 -0400 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2019-09-05 15:02:59 +0200 |
| commit | 98375b86c79137416e9fd354177b85e768c16e56 (patch) | |
| tree | 0c2cf558420c8335d0f45cb8f75f2272f6304c03 | |
| parent | 2bcdacb70327013ca2066bfcf2af1009eff01f1d (diff) | |
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.
Reported-and-tested-by: syzbot+1088533649dafa1c9004@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@vger.kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
| -rw-r--r-- | drivers/hid/hid-prodikeys.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/hid/hid-prodikeys.c b/drivers/hid/hid-prodikeys.c index 21544ebff855..5a3b3d974d84 100644 --- a/drivers/hid/hid-prodikeys.c +++ b/drivers/hid/hid-prodikeys.c @@ -551,10 +551,14 @@ static void pcmidi_setup_extra_keys( static int pcmidi_set_operational(struct pcmidi_snd *pm) { + int rc; + if (pm->ifnum != 1) return 0; /* only set up ONCE for interace 1 */ - pcmidi_get_output_report(pm); + rc = pcmidi_get_output_report(pm); + if (rc < 0) + return rc; pcmidi_submit_output_report(pm, 0xc1); return 0; } @@ -683,7 +687,11 @@ static int pcmidi_snd_initialise(struct pcmidi_snd *pm) spin_lock_init(&pm->rawmidi_in_lock); init_sustain_timers(pm); - pcmidi_set_operational(pm); + err = pcmidi_set_operational(pm); + if (err < 0) { + pk_error("failed to find output report\n"); + goto fail_register; + } /* register it */ err = snd_card_register(card); |