| Message ID | Pine.LNX.4.44L0.1909041149390.1722-100000@iolanthe.rowland.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 98375b86c79137416e9fd354177b85e768c16e56 |
| Headers | show |
| Series | HID: hid-prodikeys: Fix general protection fault during probe | expand |
On Wed, 4 Sep 2019, Alan Stern wrote: > 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> Applied, thanks a lot Alan.
Index: usb-devel/drivers/hid/hid-prodikeys.c =================================================================== --- usb-devel.orig/drivers/hid/hid-prodikeys.c +++ usb-devel/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 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);
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> --- [as1911] drivers/hid/hid-prodikeys.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)