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authorAlan Stern <stern@rowland.harvard.edu>2019-09-04 11:54:20 -0400
committerJiri Kosina <jkosina@suse.cz>2019-09-05 15:02:59 +0200
commit98375b86c79137416e9fd354177b85e768c16e56 (patch)
tree0c2cf558420c8335d0f45cb8f75f2272f6304c03 /drivers/hid/hid-prodikeys.c
parent2bcdacb70327013ca2066bfcf2af1009eff01f1d (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>
Diffstat (limited to 'drivers/hid/hid-prodikeys.c')
-rw-r--r--drivers/hid/hid-prodikeys.c12
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);