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BUG: KMSAN: uninit-value in bcsp_close+0x127/0x1e0 drivers/bluetooth/hci_bcsp.c:748
CPU: 0 PID: 18462 Comm: syz-executor.0 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_unref include/linux/skbuff.h:1017 [inline]
 kfree_skb+0x23c/0x4c0 net/core/skbuff.c:693
 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_ldisc_kill drivers/tty/tty_ldisc.c:642 [inline]
 tty_ldisc_release+0x5dd/0xdb0 drivers/tty/tty_ldisc.c:814
 tty_release_struct+0x4f/0x1d0 drivers/tty/tty_io.c:1612
 tty_release+0x1be2/0x1e80 drivers/tty/tty_io.c:1785
 __fput+0x4c9/0xba0 fs/file_table.c:280
 ____fput+0x37/0x40 fs/file_table.c:313
 task_work_run+0x22e/0x2a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:163 [inline]
 prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:194
 syscall_return_slowpath+0x90/0x610 arch/x86/entry/common.c:274
 do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x413741
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:0000000000a6fbf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000413741
RDX: 0000000000000000 RSI: 0000000000001d27 RDI: 0000000000000005
RBP: 0000000000000001 R08: 00000000fd99fd2b R09: ffffffffffffffff
R10: 0000000000a6fcd0 R11: 0000000000000293 R12: 000000000075c9a0
R13: 000000000075c9a0 R14: 0000000000760a80 R15: 000000000075bfd4

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
 ip_tunnel_xmit+0x20ed/0x3320 net/ipv4/ip_tunnel.c:827
 ipip_tunnel_xmit+0x4e2/0x7a0 net/ipv4/ipip.c:305
 __netdev_start_xmit include/linux/netdevice.h:4406 [inline]
 netdev_start_xmit include/linux/netdevice.h:4420 [inline]
 xmit_one net/core/dev.c:3280 [inline]
 dev_hard_start_xmit+0x51a/0xab0 net/core/dev.c:3296
 __dev_queue_xmit+0x394d/0x4270 net/core/dev.c:3869
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3902
 neigh_direct_output+0x42/0x50 net/core/neighbour.c:1530
 neigh_output include/net/neighbour.h:511 [inline]
 ip_finish_output2+0x1a8e/0x25d0 net/ipv4/ip_output.c:228
 ip_do_fragment+0x2d6e/0x35f0 net/ipv4/ip_output.c:849
 ip_fragment+0x246/0x410 net/ipv4/ip_output.c:587
 __ip_finish_output+0xd8b/0xda0 net/ipv4/ip_output.c:306
 ip_finish_output+0x2db/0x420 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_output+0x541/0x610 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:436 [inline]
 ip_local_out net/ipv4/ip_output.c:125 [inline]
 ip_send_skb+0x179/0x360 net/ipv4/ip_output.c:1554
 udp_send_skb+0xeda/0x1870 net/ipv4/udp.c:887
 udp_push_pending_frames net/ipv4/udp.c:915 [inline]
 udp_sendmsg+0x925/0x4170 net/ipv4/udp.c:1206
 udpv6_sendmsg+0x115d/0x4660 net/ipv6/udp.c:1277
 inet6_sendmsg+0x276/0x2e0 net/ipv6/af_inet6.c:576
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg net/socket.c:657 [inline]
 ___sys_sendmsg+0xe89/0x1590 net/socket.c:2311
 __sys_sendmmsg+0x53a/0xae0 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2439
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2439
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
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