KMSAN: uninit-value in hci_event

KMSAN: uninit-value in hci_event_packet (2)
Status: auto-closed as invalid on 2021/02/19 21:04
Reported-by: syzbot+54f68ac8e259a8af4f12@syzkaller.appspotmail.com
First crash: 307d, last: 276d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KMSAN: uninit-value in hci_event_packet (3)	C			10	27d	118d	0/22	upstream: reported C repro on 2021/03/29 15:43
upstream	KMSAN: uninit-value in hci_event_packet	C			40	344d	833d	0/22	closed as dup on 2020/07/24 21:34

Sample crash report:

=====================================================
BUG: KMSAN: uninit-value in hci_proto_connect_ind include/net/bluetooth/hci_core.h:1380 [inline]
BUG: KMSAN: uninit-value in hci_conn_request_evt net/bluetooth/hci_event.c:2699 [inline]
BUG: KMSAN: uninit-value in hci_event_packet+0x13a2c/0x39e10 net/bluetooth/hci_event.c:6062
CPU: 1 PID: 2004 Comm: kworker/u5:0 Not tainted 5.9.0-rc8-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:122
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:201
 hci_proto_connect_ind include/net/bluetooth/hci_core.h:1380 [inline]
 hci_conn_request_evt net/bluetooth/hci_event.c:2699 [inline]
 hci_event_packet+0x13a2c/0x39e10 net/bluetooth/hci_event.c:6062
 hci_rx_work+0x745/0xd20 net/bluetooth/hci_core.c:4889
 process_one_work+0x1224/0x20a0 kernel/workqueue.c:2269
 worker_thread+0x10cc/0x2740 kernel/workqueue.c:2415
 kthread+0x51c/0x560 kernel/kthread.c:293
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:129 [inline]
 kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:112
 kmsan_slab_alloc+0x8d/0xe0 mm/kmsan/kmsan_hooks.c:80
 slab_alloc_node mm/slub.c:2903 [inline]
 __kmalloc_node_track_caller+0x7de/0x1320 mm/slub.c:4507
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x309/0xae0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1094 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:389 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:165 [inline]
 vhci_write+0x18a/0x880 drivers/bluetooth/hci_vhci.c:285
 call_write_iter include/linux/fs.h:1882 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0xfba/0x1870 fs/read_write.c:586
 ksys_write+0x2af/0x4d0 fs/read_write.c:639
 __do_sys_write fs/read_write.c:651 [inline]
 __se_sys_write+0x92/0xb0 fs/read_write.c:648
 __ia32_sys_write+0x4a/0x70 fs/read_write.c:648
 do_syscall_32_irqs_on arch/x86/entry/common.c:80 [inline]
 __do_fast_syscall_32+0x129/0x180 arch/x86/entry/common.c:139
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:162
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:205
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
=====================================================

Crashes (4):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info
ci-upstream-kmsan-gce-386	2020/10/22 21:04	https://github.com/google/kmsan.git master	e16174226146	4e740c00	.config	log	report	info
ci-upstream-kmsan-gce-386	2020/10/06 23:25	https://github.com/google/kmsan.git master	5edb1df295b9	1880b4a9	.config	log	report	info
ci-upstream-kmsan-gce-386	2020/09/30 17:50	https://github.com/google/kmsan.git master	5edb1df295b9	8516f6d3	.config	log	report	info
ci-upstream-kmsan-gce-386	2020/09/21 12:51	https://github.com/google/kmsan.git master	c5a13b33ec11	9e1fa68e	.config	log	report	info