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BUG: KMSAN: use-after-free in skb_unref include/linux/skbuff.h:1011 [inline]
BUG: KMSAN: use-after-free in kfree_skb+0x23c/0x4c0 net/core/skbuff.c:693
CPU: 1 PID: 19808 Comm: syz-executor.5 Not tainted 5.4.0-rc5+ #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+0x128/0x220 mm/kmsan/kmsan_report.c:108
 __msan_warning+0x73/0xe0 mm/kmsan/kmsan_instr.c:245
 skb_unref include/linux/skbuff.h:1011 [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_set_ldisc+0x55c/0x22f0 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+0xb6/0x160 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x45a219
Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f09964ddc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a219
RDX: 00000000200001c0 RSI: 0000000000005423 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f09964de6d4
R13: 00000000004c4e89 R14: 00000000004d9d30 R15: 00000000ffffffff

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:151 [inline]
 kmsan_internal_poison_shadow+0x60/0x120 mm/kmsan/kmsan.c:134
 kmsan_slab_free+0x8d/0xf0 mm/kmsan/kmsan_hooks.c:108
 slab_free_freelist_hook mm/slub.c:1473 [inline]
 slab_free mm/slub.c:3046 [inline]
 kmem_cache_free_bulk+0x3ad9/0x3f10 mm/slub.c:3171
 __kfree_skb_flush+0xb0/0x100 net/core/skbuff.c:862
 net_rx_action+0x1a5e/0x1aa0 net/core/dev.c:6483
 __do_softirq+0x4a1/0x83a kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:375 [inline]
 irq_exit+0x230/0x280 kernel/softirq.c:416
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 do_IRQ+0x123/0x360 arch/x86/kernel/irq.c:263
 ret_from_intr+0x0/0x33
 native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline]
 arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline]
 default_idle+0x53/0x90 arch/x86/kernel/process.c:580
 arch_cpu_idle+0x25/0x30 arch/x86/kernel/process.c:571
 default_idle_call kernel/sched/idle.c:94 [inline]
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x1d5/0x780 kernel/sched/idle.c:263
 cpu_startup_entry+0x45/0x50 kernel/sched/idle.c:355
 rest_init+0x1be/0x1f0 init/main.c:452
 arch_call_rest_init+0x13/0x15
 start_kernel+0x987/0xb57 init/main.c:787
 x86_64_start_reservations+0x18/0x2e arch/x86/kernel/head64.c:490
 x86_64_start_kernel+0x81/0x84 arch/x86/kernel/head64.c:471
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241
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