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BUG: KMSAN: uninit-value in skb_unref include/linux/skbuff.h:1017 [inline]
BUG: KMSAN: uninit-value in kfree_skb+0x23c/0x4c0 net/core/skbuff.c:693
CPU: 0 PID: 11592 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+0x162/0x2d0 mm/kmsan/kmsan_report.c:109
 __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:294
 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: 0033:0x4135d1
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: 00000000004135d1
RDX: 0000000000000000 RSI: 0000000000000695 RDI: 0000000000000005
RBP: 0000000000000001 R08: 00000000e0c2c698 R09: ffffffffffffffff
R10: 0000000000a6fcd0 R11: 0000000000000293 R12: 000000000075c9a0
R13: 000000000075c9a0 R14: 0000000000761038 R15: 000000000075bf2c

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:174 [inline]
 kmsan_internal_poison_shadow+0x58/0xb0 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
 __skb_queue_purge include/linux/skbuff.h:2745 [inline]
 inet_sock_destruct+0x1fa/0xe40 net/ipv4/af_inet.c:134
 __sk_destruct+0x8c/0x890 net/core/sock.c:1695
 sk_destruct net/core/sock.c:1734 [inline]
 __sk_free+0x5af/0x640 net/core/sock.c:1745
 sk_free net/core/sock.c:1756 [inline]
 sock_put include/net/sock.h:1725 [inline]
 sk_common_release+0x2f1/0x4b0 net/core/sock.c:3190
 rawv6_close+0xd9/0x110 net/ipv6/raw.c:1245
 inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427
 inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470
 __sock_release net/socket.c:590 [inline]
 sock_close+0x156/0x460 net/socket.c:1268
 __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
 get_signal+0x31ef/0x32f0 kernel/signal.c:2528
 do_signal+0x6f/0xe10 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop arch/x86/entry/common.c:159 [inline]
 prepare_exit_to_usermode+0x2c5/0x4d0 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
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