Bluetooth: hci6: Received unexpected HCI Event 00000000
==================================================================
BUG: KASAN: use-after-free in __skb_unlink include/linux/skbuff.h:2090 [inline]
BUG: KASAN: use-after-free in __skb_dequeue include/linux/skbuff.h:2109 [inline]
BUG: KASAN: use-after-free in skb_dequeue+0x15f/0x180 net/core/skbuff.c:3159
Read of size 8 at addr ffff888014bd6d00 by task kworker/u5:0/849

CPU: 1 PID: 849 Comm: kworker/u5:0 Not tainted 5.14.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci6 hci_rx_work
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 print_address_description.constprop.0.cold+0x6c/0x2d6 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:436
 __skb_unlink include/linux/skbuff.h:2090 [inline]
 __skb_dequeue include/linux/skbuff.h:2109 [inline]
 skb_dequeue+0x15f/0x180 net/core/skbuff.c:3159
 hci_rx_work+0x6d/0xd30 net/bluetooth/hci_core.c:5084
 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Allocated by task 18803:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x81/0xa0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc_node mm/slab.c:3261 [inline]
 kmem_cache_alloc_node+0x31d/0x590 mm/slab.c:3599
 __alloc_skb+0x20b/0x340 net/core/skbuff.c:414
 alloc_skb include/linux/skbuff.h:1112 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:389 [inline]
 h4_recv_buf+0x573/0xdb0 drivers/bluetooth/hci_h4.c:181
 h4_recv+0xec/0x200 drivers/bluetooth/hci_h4.c:115
 hci_uart_tty_receive+0x24d/0x710 drivers/bluetooth/hci_ldisc.c:613
 tiocsti drivers/tty/tty_io.c:2311 [inline]
 tty_ioctl+0x8db/0x1600 drivers/tty/tty_io.c:2719
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 849:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free mm/kasan/common.c:328 [inline]
 __kasan_slab_free+0xcd/0x100 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:230 [inline]
 __cache_free mm/slab.c:3445 [inline]
 kmem_cache_free+0x68/0x200 mm/slab.c:3740
 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:699
 __kfree_skb net/core/skbuff.c:756 [inline]
 kfree_skb net/core/skbuff.c:773 [inline]
 kfree_skb+0x140/0x3f0 net/core/skbuff.c:767
 hci_event_packet+0x464/0x7c50 net/bluetooth/hci_event.c:6400
 hci_rx_work+0x4f8/0xd30 net/bluetooth/hci_core.c:5120
 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

The buggy address belongs to the object at ffff888014bd6d00
 which belongs to the cache skbuff_head_cache of size 232
The buggy address is located 0 bytes inside of
 232-byte region [ffff888014bd6d00, ffff888014bd6de8)
The buggy address belongs to the page:
page:ffffea000052f580 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888014bd6a80 pfn:0x14bd6
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea000184d988 ffffea000074f748 ffff8881400a2c00
raw: ffff888014bd6a80 ffff888014bd6080 0000000100000009 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x242220(__GFP_HIGH|__GFP_ATOMIC|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 9731, ts 2021570038124, free_ts 2005104734605
 prep_new_page mm/page_alloc.c:2436 [inline]
 get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4169
 __alloc_pages_slowpath.constprop.0+0x2e6/0x21b0 mm/page_alloc.c:4940
 __alloc_pages+0x412/0x500 mm/page_alloc.c:5404
 __alloc_pages_node include/linux/gfp.h:570 [inline]
 kmem_getpages mm/slab.c:1377 [inline]
 cache_grow_begin+0x75/0x460 mm/slab.c:2593
 cache_alloc_refill+0x27f/0x380 mm/slab.c:2965
 ____cache_alloc mm/slab.c:3048 [inline]
 ____cache_alloc mm/slab.c:3031 [inline]
 slab_alloc_node mm/slab.c:3249 [inline]
 kmem_cache_alloc_node+0x4a1/0x590 mm/slab.c:3599
 __alloc_skb+0x20b/0x340 net/core/skbuff.c:414
 alloc_skb include/linux/skbuff.h:1112 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:664 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:721 [inline]
 nsim_dev_trap_report_work+0x2ac/0xbd0 drivers/net/netdevsim/dev.c:762
 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1346 [inline]
 free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1397
 free_unref_page_prepare mm/page_alloc.c:3332 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3411
 slab_destroy mm/slab.c:1627 [inline]
 slabs_destroy+0x89/0xc0 mm/slab.c:1647
 cache_flusharray mm/slab.c:3418 [inline]
 ___cache_free+0x4c6/0x610 mm/slab.c:3480
 qlink_free mm/kasan/quarantine.c:146 [inline]
 qlist_free_all+0x4e/0x110 mm/kasan/quarantine.c:165
 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272
 __kasan_slab_alloc+0x8b/0xa0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc mm/slab.c:3323 [inline]
 __do_kmalloc mm/slab.c:3700 [inline]
 __kmalloc+0x284/0x4d0 mm/slab.c:3711
 kmalloc include/linux/slab.h:596 [inline]
 tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822
 security_inode_getattr+0xcf/0x140 security/security.c:1333
 vfs_getattr fs/stat.c:139 [inline]
 vfs_statx+0x164/0x390 fs/stat.c:207
 vfs_fstatat fs/stat.c:225 [inline]
 vfs_lstat include/linux/fs.h:3386 [inline]
 __do_sys_newlstat+0x91/0x110 fs/stat.c:380
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Memory state around the buggy address:
 ffff888014bd6c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888014bd6c80: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc
>ffff888014bd6d00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888014bd6d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
 ffff888014bd6e00: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
==================================================================