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BUG: KMSAN: use-after-free in inet_gifconf+0x469/0x4e0 net/ipv4/devinet.c:1248
CPU: 0 PID: 16962 Comm: syz-executor.4 Not tainted 5.6.0-rc2-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+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 inet_gifconf+0x469/0x4e0 net/ipv4/devinet.c:1248
 dev_ifconf+0x289/0x4c0 net/core/dev_ioctl.c:78
 compat_dev_ifconf net/socket.c:3103 [inline]
 compat_sock_ioctl_trans net/socket.c:3478 [inline]
 compat_sock_ioctl+0x2e7d/0x4ad0 net/socket.c:3588
 __do_compat_sys_ioctl fs/ioctl.c:857 [inline]
 __se_compat_sys_ioctl+0x57c/0xed0 fs/ioctl.c:808
 __ia32_compat_sys_ioctl+0xd9/0x110 fs/ioctl.c:808
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fc5d99
Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5dc00cc EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000008912
RDX: 0000000020000080 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
 kmsan_slab_free+0x6e/0xb0 mm/kmsan/kmsan_hooks.c:107
 slab_free_freelist_hook mm/slub.c:1477 [inline]
 slab_free mm/slub.c:3040 [inline]
 kfree+0x565/0x30a0 mm/slub.c:3993
 __devinet_sysctl_unregister net/ipv4/devinet.c:2593 [inline]
 devinet_sysctl_unregister net/ipv4/devinet.c:2620 [inline]
 inetdev_destroy net/ipv4/devinet.c:323 [inline]
 inetdev_event+0x1272/0x1e80 net/ipv4/devinet.c:1593
 notifier_call_chain kernel/notifier.c:83 [inline]
 __raw_notifier_call_chain kernel/notifier.c:361 [inline]
 raw_notifier_call_chain+0x12a/0x240 kernel/notifier.c:368
 call_netdevice_notifiers_info net/core/dev.c:1943 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:1955 [inline]
 call_netdevice_notifiers net/core/dev.c:1969 [inline]
 rollback_registered_many+0x1565/0x25f0 net/core/dev.c:8820
 unregister_netdevice_many net/core/dev.c:9976 [inline]
 default_device_exit_batch+0x70e/0xc20 net/core/dev.c:10452
 ops_exit_list net/core/net_namespace.c:175 [inline]
 cleanup_net+0xf27/0x1a50 net/core/net_namespace.c:589
 process_one_work+0x1555/0x1f40 kernel/workqueue.c:2264
 worker_thread+0xef6/0x2450 kernel/workqueue.c:2410
 kthread+0x4b5/0x4f0 kernel/kthread.c:256
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:353
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