KMSAN: uninit-value in legacy_dvb_usb_read_remote

KMSAN: uninit-value in legacy_dvb_usb_read_remote_control
Status: upstream: reported C repro on 2020/12/12 17:43
Reported-by: syzbot+2cd8c5db4a85f0a04142@syzkaller.appspotmail.com
First crash: 47d, last: 2d21h

Patch testing requests:
Created	Duration	User	Patch	Repo	Result
2021/01/09 19:39	23m	anant.thazhemadam@gmail.com		https://github.com/google/kmsan.git master	report log

Sample crash report:

=====================================================
BUG: KMSAN: uninit-value in legacy_dvb_usb_read_remote_control+0x3b8/0x730 drivers/media/usb/dvb-usb/dvb-usb-remote.c:129
CPU: 0 PID: 8393 Comm: kworker/0:5 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events legacy_dvb_usb_read_remote_control
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197
 legacy_dvb_usb_read_remote_control+0x3b8/0x730 drivers/media/usb/dvb-usb/dvb-usb-remote.c:129
 process_one_work+0x121c/0x1fc0 kernel/workqueue.c:2272
 worker_thread+0x10cc/0x2740 kernel/workqueue.c:2418
 kthread+0x51c/0x560 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Local variable ----state@legacy_dvb_usb_read_remote_control created at:
 legacy_dvb_usb_read_remote_control+0x68/0x730 drivers/media/usb/dvb-usb/dvb-usb-remote.c:120
 legacy_dvb_usb_read_remote_control+0x68/0x730 drivers/media/usb/dvb-usb/dvb-usb-remote.c:120
=====================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 8393 Comm: kworker/0:5 Tainted: G    B             5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events legacy_dvb_usb_read_remote_control
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 panic+0x4c8/0xea7 kernel/panic.c:231
 kmsan_report+0x1da/0x1e0 mm/kmsan/kmsan_report.c:141
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197
 legacy_dvb_usb_read_remote_control+0x3b8/0x730 drivers/media/usb/dvb-usb/dvb-usb-remote.c:129
 process_one_work+0x121c/0x1fc0 kernel/workqueue.c:2272
 worker_thread+0x10cc/0x2740 kernel/workqueue.c:2418
 kthread+0x51c/0x560 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (5):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Maintainers
ci-upstream-kmsan-gce	2020/12/08 21:26	https://github.com/google/kmsan.git master	73d62e81	a7f7f4a4	.config	log	report	syz	C		linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, mchehab@kernel.org
ci-upstream-kmsan-gce	2021/01/22 10:47	https://github.com/google/kmsan.git master	73d62e81	d4f4eca5	.config	log	report			info	linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, mchehab@kernel.org
ci-upstream-kmsan-gce-386	2021/01/22 04:44	https://github.com/google/kmsan.git master	73d62e81	d4f4eca5	.config	log	report			info	linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, mchehab@kernel.org
ci-upstream-kmsan-gce	2020/12/08 17:22	https://github.com/google/kmsan.git master	73d62e81	a7f7f4a4	.config	log	report			info	linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, mchehab@kernel.org
ci-upstream-kmsan-gce-386	2020/12/19 15:49	https://github.com/google/kmsan.git master	73d62e81	04201c06	.config	log	report			info	linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, mchehab@kernel.org