From: Vito Caputo vcaputo@pengaru.com
commit ca8f245f284eeffa56f3b7a5eb6fc503159ee028 upstream.
Don't use uninitialized ircode[] in cxusb_rc_query() when cxusb_ctrl_msg() fails to populate its contents.
syzbot reported:
dvb-usb: bulk message failed: -22 (1/-30591) ===================================================== BUG: KMSAN: uninit-value in ir_lookup_by_scancode drivers/media/rc/rc-main.c:494 [inline] BUG: KMSAN: uninit-value in rc_g_keycode_from_table drivers/media/rc/rc-main.c:582 [inline] BUG: KMSAN: uninit-value in rc_keydown+0x1a6/0x6f0 drivers/media/rc/rc-main.c:816 CPU: 1 PID: 11436 Comm: kworker/1:2 Not tainted 5.3.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events dvb_usb_read_remote_control Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x191/0x1f0 lib/dump_stack.c:113 kmsan_report+0x13a/0x2b0 mm/kmsan/kmsan_report.c:108 __msan_warning+0x73/0xe0 mm/kmsan/kmsan_instr.c:250 bsearch+0x1dd/0x250 lib/bsearch.c:41 ir_lookup_by_scancode drivers/media/rc/rc-main.c:494 [inline] rc_g_keycode_from_table drivers/media/rc/rc-main.c:582 [inline] rc_keydown+0x1a6/0x6f0 drivers/media/rc/rc-main.c:816 cxusb_rc_query+0x2e1/0x360 drivers/media/usb/dvb-usb/cxusb.c:548 dvb_usb_read_remote_control+0xf9/0x290 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261 process_one_work+0x1572/0x1ef0 kernel/workqueue.c:2269 worker_thread+0x111b/0x2460 kernel/workqueue.c:2415 kthread+0x4b5/0x4f0 kernel/kthread.c:256 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355
Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:150 [inline] kmsan_internal_chain_origin+0xd2/0x170 mm/kmsan/kmsan.c:314 __msan_chain_origin+0x6b/0xe0 mm/kmsan/kmsan_instr.c:184 rc_g_keycode_from_table drivers/media/rc/rc-main.c:583 [inline] rc_keydown+0x2c4/0x6f0 drivers/media/rc/rc-main.c:816 cxusb_rc_query+0x2e1/0x360 drivers/media/usb/dvb-usb/cxusb.c:548 dvb_usb_read_remote_control+0xf9/0x290 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261 process_one_work+0x1572/0x1ef0 kernel/workqueue.c:2269 worker_thread+0x111b/0x2460 kernel/workqueue.c:2415 kthread+0x4b5/0x4f0 kernel/kthread.c:256 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355
Local variable description: ----ircode@cxusb_rc_query Variable was created at: cxusb_rc_query+0x4d/0x360 drivers/media/usb/dvb-usb/cxusb.c:543 dvb_usb_read_remote_control+0xf9/0x290 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261
Signed-off-by: Vito Caputo vcaputo@pengaru.com Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: Sean Young sean@mess.org Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/media/usb/dvb-usb/cxusb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/media/usb/dvb-usb/cxusb.c +++ b/drivers/media/usb/dvb-usb/cxusb.c @@ -542,7 +542,8 @@ static int cxusb_rc_query(struct dvb_usb { u8 ircode[4];
- cxusb_ctrl_msg(d, CMD_GET_IR_CODE, NULL, 0, ircode, 4); + if (cxusb_ctrl_msg(d, CMD_GET_IR_CODE, NULL, 0, ircode, 4) < 0) + return 0;
if (ircode[2] || ircode[3]) rc_keydown(d->rc_dev, RC_PROTO_NEC,