==================================================================
BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511
Read of size 8 at addr ffff88801ad30480 by task kworker/u4:2/11486

CPU: 0 PID: 11486 Comm: kworker/u4:2 Not tainted 5.18.0-rc3-syzkaller-00016-gb253435746d9-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0xeb/0x467 mm/kasan/report.c:313
 print_report mm/kasan/report.c:429 [inline]
 kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491
 tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511
 tcp_write_timer_handler+0x5e6/0xbc0 net/ipv4/tcp_timer.c:622
 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
 expire_timers kernel/time/timer.c:1466 [inline]
 __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1737
 __run_timers kernel/time/timer.c:1715 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1750
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:200
Code: 48 89 ef 5d e9 a1 72 4a 00 5d be 03 00 00 00 e9 86 c0 74 02 66 0f 1f 44 00 00 48 8b be a8 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 <65> 8b 05 b9 aa 8a 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b
RSP: 0018:ffffc90004aa7058 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88804c5f0100 RSI: ffffffff815eb9c8 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff9002f907
R10: ffffffff815eb9be R11: 0000000000000000 R12: ffffffff84e0fb70
R13: 0000000000000200 R14: ffffc90004aa70b8 R15: dffffc0000000000
 console_unlock+0x82e/0xdd0 kernel/printk/printk.c:2779
 vprintk_emit+0x1b4/0x5f0 kernel/printk/printk.c:2272
 dev_vprintk_emit+0x36e/0x3b2 drivers/base/core.c:4604
 dev_printk_emit+0xba/0xf1 drivers/base/core.c:4615
 __netdev_printk+0x1c6/0x27a net/core/dev.c:11117
 netdev_info+0xd7/0x109 net/core/dev.c:11172
 nsim_udp_tunnel_unset_port.cold+0x95/0xb8 drivers/net/netdevsim/udp_tunnels.c:64
 udp_tunnel_nic_device_sync_one net/ipv4/udp_tunnel_nic.c:225 [inline]
 udp_tunnel_nic_device_sync_by_port net/ipv4/udp_tunnel_nic.c:246 [inline]
 __udp_tunnel_nic_device_sync.part.0+0xa4c/0xcb0 net/ipv4/udp_tunnel_nic.c:289
 __udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:283 [inline]
 udp_tunnel_nic_flush+0x2b4/0x5e0 net/ipv4/udp_tunnel_nic.c:668
 udp_tunnel_nic_unregister net/ipv4/udp_tunnel_nic.c:869 [inline]
 udp_tunnel_nic_netdevice_event+0x66a/0x1a60 net/ipv4/udp_tunnel_nic.c:909
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:84
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1938
 call_netdevice_notifiers_extack net/core/dev.c:1976 [inline]
 call_netdevice_notifiers net/core/dev.c:1990 [inline]
 unregister_netdevice_many+0x92e/0x1890 net/core/dev.c:10751
 unregister_netdevice_queue net/core/dev.c:10683 [inline]
 unregister_netdevice_queue+0x2dd/0x3c0 net/core/dev.c:10673
 unregister_netdevice include/linux/netdevice.h:2954 [inline]
 nsim_destroy+0x3f/0x190 drivers/net/netdevsim/netdev.c:382
 __nsim_dev_port_del+0x191/0x250 drivers/net/netdevsim/dev.c:1427
 nsim_dev_port_del_all+0x85/0xe0 drivers/net/netdevsim/dev.c:1440
 nsim_dev_reload_destroy+0x11f/0x420 drivers/net/netdevsim/dev.c:1659
 nsim_dev_reload_down+0xdf/0x180 drivers/net/netdevsim/dev.c:962
 devlink_reload+0x1c2/0x6b0 net/core/devlink.c:4070
 devlink_pernet_pre_exit+0x17e/0x220 net/core/devlink.c:11476
 ops_pre_exit_list net/core/net_namespace.c:152 [inline]
 cleanup_net+0x451/0xb00 net/core/net_namespace.c:582
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>

Allocated by task 3885:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:436 [inline]
 __kasan_slab_alloc+0x85/0xb0 mm/kasan/common.c:469
 kasan_slab_alloc include/linux/kasan.h:224 [inline]
 slab_post_alloc_hook mm/slab.h:749 [inline]
 slab_alloc mm/slab.c:3316 [inline]
 __kmem_cache_alloc_lru mm/slab.c:3493 [inline]
 kmem_cache_alloc+0x265/0x560 mm/slab.c:3513
 kmem_cache_zalloc include/linux/slab.h:704 [inline]
 net_alloc net/core/net_namespace.c:403 [inline]
 copy_net_ns+0x125/0x760 net/core/net_namespace.c:458
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x445/0x920 kernel/fork.c:3132
 __do_sys_unshare kernel/fork.c:3203 [inline]
 __se_sys_unshare kernel/fork.c:3201 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3201
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 11486:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:45
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free+0x13d/0x180 mm/kasan/common.c:328
 kasan_slab_free include/linux/kasan.h:200 [inline]
 __cache_free mm/slab.c:3439 [inline]
 kmem_cache_free.part.0+0xa9/0x240 mm/slab.c:3749
 net_free net/core/net_namespace.c:432 [inline]
 net_free net/core/net_namespace.c:428 [inline]
 cleanup_net+0x8ba/0xb00 net/core/net_namespace.c:615
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Last potentially related work creation:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348
 insert_work+0x48/0x350 kernel/workqueue.c:1358
 __queue_work+0x62e/0x1140 kernel/workqueue.c:1517
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
 expire_timers kernel/time/timer.c:1461 [inline]
 __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1737
 __run_timers kernel/time/timer.c:1715 [inline]
 run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1752
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558

Second to last potentially related work creation:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348
 insert_work+0x48/0x350 kernel/workqueue.c:1358
 __queue_work+0x62e/0x1140 kernel/workqueue.c:1517
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
 expire_timers kernel/time/timer.c:1461 [inline]
 __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1737
 __run_timers kernel/time/timer.c:1715 [inline]
 run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1752
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558

The buggy address belongs to the object at ffff88801ad301c0
 which belongs to the cache net_namespace of size 6784
The buggy address is located 704 bytes inside of
 6784-byte region [ffff88801ad301c0, ffff88801ad31c40)

The buggy address belongs to the physical page:
page:ffffea00006b4c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1ad30
head:ffffea00006b4c00 order:1 compound_mapcount:0 compound_pincount:0
memcg:ffff88807f2a1e41
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0000726508 ffff8880114e3f50 ffff8880114d3600
raw: 0000000000000000 ffff88801ad301c0 0000000100000001 ffff88807f2a1e41
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x3420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 3885, tgid 3885 (syz-executor.0), ts 66206628827, free_ts 58584232453
 prep_new_page mm/page_alloc.c:2441 [inline]
 get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408
 __alloc_pages_node include/linux/gfp.h:587 [inline]
 kmem_getpages mm/slab.c:1378 [inline]
 cache_grow_begin+0x75/0x350 mm/slab.c:2584
 cache_alloc_refill+0x27f/0x380 mm/slab.c:2957
 ____cache_alloc mm/slab.c:3040 [inline]
 ____cache_alloc mm/slab.c:3023 [inline]
 __do_cache_alloc mm/slab.c:3267 [inline]
 slab_alloc mm/slab.c:3309 [inline]
 __kmem_cache_alloc_lru mm/slab.c:3493 [inline]
 kmem_cache_alloc+0x450/0x560 mm/slab.c:3513
 kmem_cache_zalloc include/linux/slab.h:704 [inline]
 net_alloc net/core/net_namespace.c:403 [inline]
 copy_net_ns+0x125/0x760 net/core/net_namespace.c:458
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x445/0x920 kernel/fork.c:3132
 __do_sys_unshare kernel/fork.c:3203 [inline]
 __se_sys_unshare kernel/fork.c:3201 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3201
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1356 [inline]
 free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1406
 free_unref_page_prepare mm/page_alloc.c:3328 [inline]
 free_unref_page+0x19/0x6a0 mm/page_alloc.c:3423
 slab_destroy mm/slab.c:1630 [inline]
 slabs_destroy+0x89/0xc0 mm/slab.c:1650
 cache_flusharray mm/slab.c:3411 [inline]
 ___cache_free+0x34e/0x670 mm/slab.c:3474
 qlink_free mm/kasan/quarantine.c:157 [inline]
 qlist_free_all+0x4f/0x1b0 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x97/0xb0 mm/kasan/common.c:446
 kasan_slab_alloc include/linux/kasan.h:224 [inline]
 slab_post_alloc_hook mm/slab.h:749 [inline]
 slab_alloc mm/slab.c:3316 [inline]
 __kmem_cache_alloc_lru mm/slab.c:3493 [inline]
 kmem_cache_alloc+0x265/0x560 mm/slab.c:3513
 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138
 getname_flags+0x9a/0xe0 include/linux/audit.h:323
 vfs_fstatat+0x73/0xb0 fs/stat.c:254
 __do_sys_newfstatat+0x91/0x110 fs/stat.c:425
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Memory state around the buggy address:
 ffff88801ad30380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801ad30400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801ad30480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88801ad30500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801ad30580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	48 89 ef             	mov    %rbp,%rdi
   3:	5d                   	pop    %rbp
   4:	e9 a1 72 4a 00       	jmpq   0x4a72aa
   9:	5d                   	pop    %rbp
   a:	be 03 00 00 00       	mov    $0x3,%esi
   f:	e9 86 c0 74 02       	jmpq   0x274c09a
  14:	66 0f 1f 44 00 00    	nopw   0x0(%rax,%rax,1)
  1a:	48 8b be a8 01 00 00 	mov    0x1a8(%rsi),%rdi
  21:	e8 b4 ff ff ff       	callq  0xffffffda
  26:	31 c0                	xor    %eax,%eax
  28:	c3                   	retq
  29:	90                   	nop
* 2a:	65 8b 05 b9 aa 8a 7e 	mov    %gs:0x7e8aaab9(%rip),%eax        # 0x7e8aaaea <-- trapping instruction
  31:	89 c1                	mov    %eax,%ecx
  33:	48 8b 34 24          	mov    (%rsp),%rsi
  37:	81 e1 00 01 00 00    	and    $0x100,%ecx
  3d:	65                   	gs
  3e:	48                   	rex.W
  3f:	8b                   	.byte 0x8b