bisecting fixing commit since 3c8c23092588a23bf1856a64f58c37f477a413be
building syzkaller on 8bdd5343e64460868dd1318257a39f1e7fd89471
testing commit 3c8c23092588a23bf1856a64f58c37f477a413be with gcc (GCC) 8.4.1 20210217
kernel signature: 0dd43082300c9e3af9ed9005896c68eb95e073b80c57212c623498d987636b59
all runs: crashed: KASAN: slab-out-of-bounds Read in hci_le_meta_evt
testing current HEAD 9a2dc0e6c531d595bcdf2c66d0be131679bd02df
testing commit 9a2dc0e6c531d595bcdf2c66d0be131679bd02df with gcc (GCC) 8.4.1 20210217
kernel signature: 98ff986279974b8270097e1f96b711d006f93351a969205bcf6dbaa96fa3a357
all runs: crashed: KASAN: slab-out-of-bounds Read in hci_le_meta_evt
revisions tested: 2, total time: 29m33.735029463s (build: 21m47.512999331s, test: 7m17.432899622s)
the crash still happens on HEAD
commit msg: Linux 4.19.194
crash: KASAN: slab-out-of-bounds Read in hci_le_meta_evt
Bluetooth: hci5: Dropping invalid advertising data
Bluetooth: hci5: Dropping invalid advertising data
==================================================================
IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready
BUG: KASAN: slab-out-of-bounds in hci_le_adv_report_evt net/bluetooth/hci_event.c:5337 [inline]
BUG: KASAN: slab-out-of-bounds in hci_le_meta_evt+0x301c/0x3cd0 net/bluetooth/hci_event.c:5637
Read of size 1 at addr ffff8880971a650a by task kworker/u5:1/8124
IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready

CPU: 0 PID: 8124 Comm: kworker/u5:1 Not tainted 4.19.194-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci5 hci_rx_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x17c/0x226 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 mm/kasan/report.c:412 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:396
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
 hci_le_adv_report_evt net/bluetooth/hci_event.c:5337 [inline]
 hci_le_meta_evt+0x301c/0x3cd0 net/bluetooth/hci_event.c:5637
 hci_event_packet+0x29fa/0x68e0 net/bluetooth/hci_event.c:5902
IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
 hci_rx_work+0x385/0xa70 net/bluetooth/hci_core.c:4366
 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2152
 worker_thread+0x85/0xb60 kernel/workqueue.c:2295
 kthread+0x347/0x410 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Allocated by task 9942:
 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
 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
 vfs_write+0x150/0x4d0 fs/read_write.c:549
 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 ffff8880971a6300
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 10 bytes to the right of
 512-byte region [ffff8880971a6300, ffff8880971a6500)
The buggy address belongs to the page:
page:ffffea00025c6980 count:1 mapcount:0 mapping:ffff88813bff6940 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea0002d2b688 ffffea0002d35888 ffff88813bff6940
raw: 0000000000000000 ffff8880971a6080 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880971a6400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880971a6480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880971a6500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff8880971a6580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880971a6600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================