bisecting fixing commit since f6d5cb9e2c06f7d583dd9f4f7cca21d13d78c32a
building syzkaller on 816e0689d7d9d8321f8bf360740f0e516aee15ca
testing commit f6d5cb9e2c06f7d583dd9f4f7cca21d13d78c32a with gcc (GCC) 8.1.0
kernel signature: ecf528a5bf9f54a6752f09a42ab99163e68a55f252e8a1c887d86e8ab3491b5f
all runs: crashed: KASAN: slab-out-of-bounds Read in hci_le_meta_evt
testing current HEAD ad326970d25cc85128cd22d62398751ad072efff
testing commit ad326970d25cc85128cd22d62398751ad072efff with gcc (GCC) 8.1.0
kernel signature: fb2bcd4c4c60b7215867048a74ab9682f176b8b12d6554f13129900dd00718e1
all runs: crashed: KASAN: slab-out-of-bounds Read in hci_le_meta_evt
revisions tested: 2, total time: 23m38.747943786s (build: 16m49.46072122s, test: 6m12.301416113s)
the crash still happens on HEAD
commit msg: Linux 4.19.152
crash: KASAN: slab-out-of-bounds Read in hci_le_meta_evt
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
==================================================================
BUG: KASAN: slab-out-of-bounds in hci_le_direct_adv_report_evt net/bluetooth/hci_event.c:5608 [inline]
BUG: KASAN: slab-out-of-bounds in hci_le_meta_evt+0x2e9f/0x3950 net/bluetooth/hci_event.c:5649
Read of size 1 at addr ffff8880b49e0a4c by task kworker/u5:7/6662

CPU: 1 PID: 6662 Comm: kworker/u5:7 Not tainted 4.19.152-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci1 hci_rx_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x17c/0x22a lib/dump_stack.c:118
 print_address_description.cold.6+0x9/0x211 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x307 mm/kasan/report.c:412
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
Bluetooth: hci2: unknown advertising packet type: 0x88
 hci_le_direct_adv_report_evt net/bluetooth/hci_event.c:5608 [inline]
 hci_le_meta_evt+0x2e9f/0x3950 net/bluetooth/hci_event.c:5649
Bluetooth: hci2: unknown advertising packet type: 0x4e
Bluetooth: hci2: unknown advertising packet type: 0xff
 hci_event_packet+0x2d31/0x7215 net/bluetooth/hci_event.c:5898
Bluetooth: hci2: unknown advertising packet type: 0xff
Bluetooth: hci2: unknown advertising packet type: 0x88
Bluetooth: hci2: unknown advertising packet type: 0x88
 hci_rx_work+0x31b/0x8e0 net/bluetooth/hci_core.c:4359
 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2155
Bluetooth: hci2: unknown advertising packet type: 0xff
Bluetooth: hci2: unknown advertising packet type: 0xff
 worker_thread+0x85/0xb60 kernel/workqueue.c:2298
 kthread+0x347/0x410 kernel/kthread.c:259
Bluetooth: hci2: unknown advertising packet type: 0x88
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Allocated by task 7930:
 save_stack mm/kasan/kasan.c:448 [inline]
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:553
Bluetooth: hci2: unknown advertising packet type: 0xff
 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:538
 __do_kmalloc_node mm/slab.c:3689 [inline]
 __kmalloc_node_track_caller+0x50/0x70 mm/slab.c:3703
 __kmalloc_reserve.isra.9+0x2c/0xc0 net/core/skbuff.c:137
 __alloc_skb+0xd7/0x580 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:995 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:339 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:180 [inline]
 vhci_write+0xa8/0x3e0 drivers/bluetooth/hci_vhci.c:299
 call_write_iter include/linux/fs.h:1821 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x443/0x890 fs/read_write.c:487
IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready
 vfs_write+0x150/0x4d0 fs/read_write.c:549
batman_adv: batadv0: Interface activated: batadv_slave_1
 ksys_write+0x103/0x260 fs/read_write.c:599
 __do_sys_write fs/read_write.c:611 [inline]
 __se_sys_write fs/read_write.c:608 [inline]
 __x64_sys_write+0x6e/0xb0 fs/read_write.c:608
 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8880b49e0840
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 12 bytes to the right of
 512-byte region [ffff8880b49e0840, ffff8880b49e0a40)
The buggy address belongs to the page:
page:ffffea0002d27800 count:1 mapcount:0 mapping:ffff88813be9c940 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffffea000294dbc8 ffffea0002463b08 ffff88813be9c940
raw: 0000000000000000 ffff8880b49e00c0 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880b49e0900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880b49e0980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880b49e0a00: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                              ^
 ffff8880b49e0a80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff8880b49e0b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================