=====================================================
BUG: KMSAN: uninit-value in bcsp_close+0xb9/0x1e0 drivers/bluetooth/hci_bcsp.c:744
CPU: 1 PID: 26688 Comm: syz-executor.3 Not tainted 5.3.0-rc7+ #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+0x191/0x1f0 lib/dump_stack.c:113
 kmsan_report+0x13a/0x2b0 mm/kmsan/kmsan_report.c:108
 __msan_warning+0x73/0xe0 mm/kmsan/kmsan_instr.c:250
 __skb_unlink include/linux/skbuff.h:2016 [inline]
 __skb_dequeue include/linux/skbuff.h:2031 [inline]
 skb_dequeue net/core/skbuff.c:3034 [inline]
 skb_queue_purge+0x3e2/0x480 net/core/skbuff.c:3071
 bcsp_close+0xb9/0x1e0 drivers/bluetooth/hci_bcsp.c:744
 hci_uart_tty_close+0x385/0x410 drivers/bluetooth/hci_ldisc.c:548
 tty_ldisc_close drivers/tty/tty_ldisc.c:494 [inline]
 tty_set_ldisc+0x55c/0x23e0 drivers/tty/tty_ldisc.c:590
 tiocsetd drivers/tty/tty_io.c:2334 [inline]
 tty_ioctl+0x1bc1/0x3100 drivers/tty/tty_io.c:2594
 do_vfs_ioctl+0xea8/0x2c50 fs/ioctl.c:46
 ksys_ioctl fs/ioctl.c:713 [inline]
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:718
 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:718
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x459a29
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fe5671dec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459a29
RDX: 00000000200001c0 RSI: 0000000000005423 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe5671df6d4
R13: 00000000004c435f R14: 00000000004d8a10 R15: 00000000ffffffff

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:150 [inline]
 kmsan_internal_poison_shadow+0x53/0x100 mm/kmsan/kmsan.c:134
 kmsan_slab_free+0x8d/0x100 mm/kmsan/kmsan_hooks.c:123
 slab_free_freelist_hook mm/slub.c:1472 [inline]
 slab_free mm/slub.c:3038 [inline]
 kmem_cache_free+0x2d1/0x2b70 mm/slub.c:3054
 kfree_skbmem net/core/skbuff.c:644 [inline]
 __kfree_skb net/core/skbuff.c:680 [inline]
 kfree_skb+0x473/0x4c0 net/core/skbuff.c:697
 bcsp_close+0x127/0x1e0 drivers/bluetooth/hci_bcsp.c:748
 hci_uart_tty_close+0x385/0x410 drivers/bluetooth/hci_ldisc.c:548
 tty_ldisc_close drivers/tty/tty_ldisc.c:494 [inline]
 tty_set_ldisc+0x55c/0x23e0 drivers/tty/tty_ldisc.c:590
 tiocsetd drivers/tty/tty_io.c:2334 [inline]
 tty_ioctl+0x1bc1/0x3100 drivers/tty/tty_io.c:2594
 do_vfs_ioctl+0xea8/0x2c50 fs/ioctl.c:46
 ksys_ioctl fs/ioctl.c:713 [inline]
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:718
 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:718
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
=====================================================