KMSAN: uninit-value in process_adv

KMSAN: uninit-value in process_adv_report
Status: upstream: reported C repro on 2020/08/02 20:46
Reported-by: syzbot+e4244d85e5b777ac4d3d@syzkaller.appspotmail.com
First crash: 321d, last: 174d

Patch testing requests:
Created	Duration	User	Patch	Repo	Result
2020/09/03 23:08	14m	dragonjetli@gmail.com	patch	https://github.com/google/kmsan.git master	report log
2020/09/02 23:47	14m	dragonjetli@gmail.com		https://github.com/google/kmsan.git master	report log

Sample crash report:

Bluetooth: hci0: unknown advertising packet type: 0x2b
=====================================================
BUG: KMSAN: uninit-value in hci_bdaddr_is_rpa include/net/bluetooth/hci_core.h:1486 [inline]
BUG: KMSAN: uninit-value in process_adv_report+0x8e4/0x24e0 net/bluetooth/hci_event.c:5409
CPU: 0 PID: 2273 Comm: kworker/u5:0 Not tainted 5.8.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci0 hci_rx_work
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:121
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 hci_bdaddr_is_rpa include/net/bluetooth/hci_core.h:1486 [inline]
 process_adv_report+0x8e4/0x24e0 net/bluetooth/hci_event.c:5409
 hci_le_direct_adv_report_evt net/bluetooth/hci_event.c:5837 [inline]
 hci_le_meta_evt net/bluetooth/hci_event.c:5902 [inline]
 hci_event_packet+0xad34/0x39d30 net/bluetooth/hci_event.c:6155
 hci_rx_work+0x6df/0xd30 net/bluetooth/hci_core.c:4705
 process_one_work+0x1688/0x2140 kernel/workqueue.c:2269
 worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415
 kthread+0x551/0x590 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80
 slab_alloc_node mm/slub.c:2839 [inline]
 __kmalloc_node_track_caller+0xeab/0x12e0 mm/slub.c:4478
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x35f/0xb30 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1083 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:377 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:165 [inline]
 vhci_write+0x18a/0x890 drivers/bluetooth/hci_vhci.c:285
 call_write_iter include/linux/fs.h:1908 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0xf9a/0x17c0 fs/read_write.c:578
 ksys_write+0x275/0x500 fs/read_write.c:631
 __do_sys_write fs/read_write.c:643 [inline]
 __se_sys_write+0x92/0xb0 fs/read_write.c:640
 __x64_sys_write+0x4a/0x70 fs/read_write.c:640
 do_syscall_64+0xad/0x160 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
=====================================================

Crashes (10):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info
ci-upstream-kmsan-gce	2020/08/15 10:25	https://github.com/google/kmsan.git master	ce8056d1	424dd8e7	.config	log	report	syz	C
ci-upstream-kmsan-gce	2020/08/15 09:45	https://github.com/google/kmsan.git master	ce8056d1	424dd8e7	.config	log	report	syz	C
ci-upstream-kmsan-gce-386	2020/08/02 19:53	https://github.com/google/kmsan.git master	93f54a72	63a73341	.config	log	report	syz	C
ci-upstream-kmsan-gce	2020/12/27 23:54	https://github.com/google/kmsan.git master	73d62e81	2242f77f	.config	log	report			info
ci-upstream-kmsan-gce	2020/10/09 00:51	https://github.com/google/kmsan.git master	5edb1df2	92390980	.config	log	report			info
ci-upstream-kmsan-gce-386	2020/08/07 15:05	https://github.com/google/kmsan.git master	93f54a72	cb436c69	.config	log	report
ci-upstream-kmsan-gce-386	2020/08/07 14:41	https://github.com/google/kmsan.git master	93f54a72	cb436c69	.config	log	report
ci-upstream-kmsan-gce-386	2020/08/02 16:48	https://github.com/google/kmsan.git master	93f54a72	63a73341	.config	log	report
ci-upstream-kmsan-gce-386	2020/08/02 12:27	https://github.com/google/kmsan.git master	93f54a72	63a73341	.config	log	report
ci-upstream-kmsan-gce-386	2020/08/02 11:32	https://github.com/google/kmsan.git master	93f54a72	63a73341	.config	log	report