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When a Wacom tablet is created via UHID with parameters that route through wacom_bpt_irq() -> wacom_intuos_irq() -> wacom_intuos_pad(), but probe did not allocate pad_input, the call to wacom_report_numbered_buttons() passes a NULL input_dev, causing a general protection fault in input_get_drvdata(). Add a NULL check for pad_input at the top of wacom_intuos_pad() to bail out early when the pad input device was not set up. The bug was found by syzkaller and confirmed on a Pixel 9 Pro (Android 16, kernel 6.1.124) where it causes an immediate kernel panic and reboot via /dev/uhid without requiring root privileges: KP: Oops: Fatal exception: comm:wacom_27qhdt Reboot reason: 0xbaba - Kernel PANIC Reproducer (unprivileged): open("/dev/uhid", O_RDWR) write(fd, UHID_CREATE2{vendor=3D0x056a, product=3D0x0020}) write(fd, UHID_INPUT2{report_id=3D0x0c, size=3D10}) Fixes: c7f0522a1ad1 ("HID: wacom: Slim down wacom_intuos_pad processing") Signed-off-by: Jinmo Yang --- drivers/hid/wacom_wac.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c index da1f0ea85..251ddda3e 100644 --- a/drivers/hid/wacom_wac.c +++ b/drivers/hid/wacom_wac.c @@ -515,7 +515,6 @@ static int wacom_intuos_pad(struct wacom_wac *wacom) struct wacom_features *features =3D &wacom->features; unsigned char *data =3D wacom->data; struct input_dev *input =3D wacom->pad_input; - int i; int buttons =3D 0, nbuttons =3D features->numbered_buttons; int keys =3D 0, nkeys =3D 0; int ring1 =3D 0, ring2 =3D 0; @@ -523,6 +522,10 @@ static int wacom_intuos_pad(struct wacom_wac *wacom) bool prox =3D false; bool wrench =3D false, keyboard =3D false, mute_touch =3D false, menu =3D= false, info =3D false; + int i; + + if (!input) + return 0; =20 /* pad packets. Works as a second tool and is always in prox */ if (!(data[0] =3D=3D WACOM_REPORT_INTUOSPAD || data[0] =3D=3D WACOM_REPOR= T_INTUOS5PAD || --=20 2.53.0