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BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline]
BUG: KASAN: use-after-free in tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596
Read of size 4 at addr ffff88808977e6d0 by task syz-executor.3/24733

CPU: 0 PID: 24733 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:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351
 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482
 kasan_report+0x12/0x17 mm/kasan/common.c:618
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131
 tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline]
 tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596
 tcp_write_timer+0xa8/0x1e0 net/ipv4/tcp_timer.c:612
 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1322
 expire_timers kernel/time/timer.c:1366 [inline]
 __run_timers kernel/time/timer.c:1685 [inline]
 __run_timers kernel/time/timer.c:1653 [inline]
 run_timer_softirq+0x697/0x17a0 kernel/time/timer.c:1698
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x19b/0x1e0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:537 [inline]
 smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1133
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:768 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x95/0xe0 kernel/locking/spinlock.c:191
Code: 48 c7 c0 50 f4 d2 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 39 48 83 3d 72 d9 94 01 00 74 24 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 bc a6 10 fa 65 8b 05 0d e3 c3 78
RSP: 0018:ffff88804dec76f8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff11a5e8a RBX: 0000000000000286 RCX: 1ffffffff134b5ce
RDX: dffffc0000000000 RSI: ffffffff8177f1ae RDI: 0000000000000286
RBP: ffff88804dec7708 R08: ffff88808f99a040 R09: ffffed100cedf310
R10: ffffed100cedf30f R11: ffff8880676f987b R12: ffff8880676f9878
R13: 0000000000000286 R14: ffff8880676f9878 R15: ffffea0001ff0788
 spin_unlock_irqrestore include/linux/spinlock.h:393 [inline]
 delete_from_page_cache+0x15a/0x270 mm/filemap.c:272
 truncate_inode_page+0x8e/0xd0 mm/truncate.c:228
 shmem_undo_range+0xcb3/0x2160 mm/shmem.c:849
 shmem_truncate_range+0x27/0xa0 mm/shmem.c:977
 shmem_evict_inode+0x311/0xad0 mm/shmem.c:1077
 evict+0x306/0x680 fs/inode.c:571
 iput_final fs/inode.c:1560 [inline]
 iput+0x530/0x8b0 fs/inode.c:1586
 dentry_unlink_inode+0x2d9/0x400 fs/dcache.c:374
 __dentry_kill+0x38b/0x600 fs/dcache.c:579
 dentry_kill fs/dcache.c:686 [inline]
 dput+0x819/0xde0 fs/dcache.c:859
 __fput+0x424/0x890 fs/file_table.c:293
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x92f/0x2e50 kernel/exit.c:879
 do_group_exit+0x135/0x360 kernel/exit.c:983
 __do_sys_exit_group kernel/exit.c:994 [inline]
 __se_sys_exit_group kernel/exit.c:992 [inline]
 __x64_sys_exit_group+0x44/0x50 kernel/exit.c:992
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459879
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:00007ffe63ef8b68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000001e RCX: 0000000000459879
RDX: 0000000000413561 RSI: fffffffffffffff7 RDI: 0000000000000000
RBP: 0000000000000000 R08: 000000009cb1f87e R09: 00007ffe63ef8bc0
R10: ffffffff8128fd68 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe63ef8bc0 R14: 0000000000000000 R15: 00007ffe63ef8bd0

Allocated by task 9797:
 save_stack+0x23/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc mm/kasan/common.c:493 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:466
 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:501
 slab_post_alloc_hook mm/slab.h:520 [inline]
 slab_alloc mm/slab.c:3319 [inline]
 kmem_cache_alloc+0x121/0x710 mm/slab.c:3483
 kmem_cache_zalloc include/linux/slab.h:738 [inline]
 net_alloc net/core/net_namespace.c:410 [inline]
 copy_net_ns+0xf1/0x41f net/core/net_namespace.c:462
 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:103
 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:202
 ksys_unshare+0x444/0x980 kernel/fork.c:2831
 __do_sys_unshare kernel/fork.c:2899 [inline]
 __se_sys_unshare kernel/fork.c:2897 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:2897
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 22667:
 save_stack+0x23/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:455
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:463
 __cache_free mm/slab.c:3425 [inline]
 kmem_cache_free+0x86/0x320 mm/slab.c:3693
 net_free net/core/net_namespace.c:438 [inline]
 net_drop_ns.part.0+0x70/0x90 net/core/net_namespace.c:445
 net_drop_ns net/core/net_namespace.c:444 [inline]
 cleanup_net+0x774/0xa60 net/core/net_namespace.c:613
 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff88808977e100
 which belongs to the cache net_namespace of size 6784
The buggy address is located 1488 bytes inside of
 6784-byte region [ffff88808977e100, ffff88808977fb80)
The buggy address belongs to the page:
page:ffffea000225df80 refcount:1 mapcount:0 mapping:ffff88821b69e1c0 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea0002226888 ffffea0001bb3c88 ffff88821b69e1c0
raw: 0000000000000000 ffff88808977e100 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808977e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808977e600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88808977e680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff88808977e700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808977e780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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