audit: type=1804 audit(1615853934.671:27): pid=11236 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir113006157/syzkaller.lhQlUf/21/file0/file0" dev="loop1" ino=5 res=1
==================================================================
BUG: KASAN: use-after-free in atomic_sub_return include/asm-generic/atomic-instrumented.h:305 [inline]
BUG: KASAN: use-after-free in skb_release_data+0x120/0x920 net/core/skbuff.c:572
Write of size 4 at addr ffff8880936398e0 by task syz-executor.3/11248

CPU: 1 PID: 11248 Comm: syz-executor.3 Not tainted 4.19.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report+0x8f/0xa0 mm/kasan/report.c:412
 atomic_sub_return include/asm-generic/atomic-instrumented.h:305 [inline]
 skb_release_data+0x120/0x920 net/core/skbuff.c:572
 skb_release_all net/core/skbuff.c:640 [inline]
 __kfree_skb net/core/skbuff.c:654 [inline]
 kfree_skb+0x11a/0x3d0 net/core/skbuff.c:672
 hci_dev_do_open+0xaf0/0x1260 net/bluetooth/hci_core.c:1511
 hci_dev_open+0x130/0x250 net/bluetooth/hci_core.c:1577
 hci_sock_ioctl+0x57e/0x7d0 net/bluetooth/hci_sock.c:1018
 sock_do_ioctl+0xcb/0x2d0 net/socket.c:950
 sock_ioctl+0x2ef/0x5d0 net/socket.c:1074
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x465d27
Code: 3c 1c 48 f7 d8 49 39 c4 72 b8 e8 a4 4d 02 00 85 c0 78 bd 48 83 c4 08 4c 89 e0 5b 41 5c c3 0f 1f 44 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffe5cf19e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000001f383bc RCX: 0000000000465d27
RDX: 0000000000000003 RSI: 00000000400448c9 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 00007f1b88c12700
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 000000000056ca68 R14: 0000000000000000 R15: 0000000000400538

Allocated by task 11248:
 __do_kmalloc_node mm/slab.c:3689 [inline]
 __kmalloc_node_track_caller+0x4c/0x70 mm/slab.c:3703
 __kmalloc_reserve net/core/skbuff.c:137 [inline]
 __alloc_skb+0xae/0x560 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:995 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:339 [inline]
 hci_prepare_cmd+0x2a/0x290 net/bluetooth/hci_request.c:292
 hci_req_add_ev+0xdc/0x220 net/bluetooth/hci_request.c:326
 bredr_setup net/bluetooth/hci_core.c:293 [inline]
 hci_init2_req+0x667/0x8b0 net/bluetooth/hci_core.c:422
 __hci_req_sync+0x133/0x8a0 net/bluetooth/hci_request.c:205
 __hci_init net/bluetooth/hci_core.c:874 [inline]
 hci_dev_do_open+0xe0d/0x1260 net/bluetooth/hci_core.c:1465
 hci_dev_open+0x130/0x250 net/bluetooth/hci_core.c:1577
 hci_sock_ioctl+0x57e/0x7d0 net/bluetooth/hci_sock.c:1018
 sock_do_ioctl+0xcb/0x2d0 net/socket.c:950
 sock_ioctl+0x2ef/0x5d0 net/socket.c:1074
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8147:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 skb_free_head net/core/skbuff.c:563 [inline]
 skb_release_data+0x6de/0x920 net/core/skbuff.c:583
 skb_release_all net/core/skbuff.c:640 [inline]
 __kfree_skb net/core/skbuff.c:654 [inline]
 kfree_skb+0x11a/0x3d0 net/core/skbuff.c:672
 hci_cmd_work+0x182/0x360 net/bluetooth/hci_core.c:4395
 process_one_work+0x864/0x1570 kernel/workqueue.c:2152
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2295
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

The buggy address belongs to the object at ffff888093639800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 224 bytes inside of
 512-byte region [ffff888093639800, ffff888093639a00)
The buggy address belongs to the page:
page:ffffea00024d8e40 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea0002a48948 ffffea0002a1ee48 ffff88813bff0940
raw: 0000000000000000 ffff888093639080 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888093639780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888093639800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888093639880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff888093639900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888093639980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================