==================================================================
BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2f87/0x3400 net/ipv4/tcp_timer.c:509
Read of size 8 at addr ffff888045e902c0 by task syz-executor.5/7555

CPU: 1 PID: 7555 Comm: syz-executor.5 Not tainted 5.19.0-syzkaller-14021-gb979f005d9b1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:317 [inline]
 print_report.cold+0x2ba/0x719 mm/kasan/report.c:433
 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495
 tcp_retransmit_timer+0x2f87/0x3400 net/ipv4/tcp_timer.c:509
 tcp_write_timer_handler net/ipv4/tcp_timer.c:620 [inline]
 tcp_write_timer_handler+0x4de/0x9f0 net/ipv4/tcp_timer.c:594
 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:637
 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1519 [inline]
 __run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790
 __run_timers kernel/time/timer.c:1768 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803
 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:lock_acquire+0x1ef/0x570 kernel/locking/lockdep.c:5634
Code: fc a2 7e 83 f8 01 0f 85 e8 02 00 00 9c 58 f6 c4 02 0f 85 fb 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc900058cf7c0 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff92000b19efa RCX: 7d168befc97a58b5
RDX: 1ffff11005641c5e RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff908db947
R10: fffffbfff211b728 R11: 1ffffffff17f2709 R12: 0000000000000002
R13: 0000000000000000 R14: ffffffff8bf89240 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:280 [inline]
 rcu_read_lock include/linux/rcupdate.h:706 [inline]
 inet_twsk_purge+0x117/0x850 net/ipv4/inet_timewait_sock.c:270
 ops_exit_list+0x125/0x170 net/core/net_namespace.c:168
 setup_net+0x7fb/0xc50 net/core/net_namespace.c:349
 copy_net_ns+0x318/0x760 net/core/net_namespace.c:472
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 copy_namespaces+0x391/0x480 kernel/nsproxy.c:178
 copy_process+0x305c/0x7090 kernel/fork.c:2259
 kernel_clone+0xe7/0xab0 kernel/fork.c:2673
 __do_sys_clone+0xba/0x100 kernel/fork.c:2807
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f41b5489279
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f41b662b118 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f41b559c050 RCX: 00007f41b5489279
RDX: 0000000000000000 RSI: 00002a452cb9d040 RDI: 0000000050000000
RBP: 00007f41b54e3189 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ffc49b4accf R14: 00007f41b662b300 R15: 0000000000022000
 </TASK>

Allocated by task 3643:
 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:437 [inline]
 __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:470
 kasan_slab_alloc include/linux/kasan.h:224 [inline]
 slab_post_alloc_hook mm/slab.h:727 [inline]
 slab_alloc_node mm/slub.c:3243 [inline]
 slab_alloc mm/slub.c:3251 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3258 [inline]
 kmem_cache_alloc+0x267/0x3b0 mm/slub.c:3268
 kmem_cache_zalloc include/linux/slab.h:723 [inline]
 net_alloc net/core/net_namespace.c:404 [inline]
 copy_net_ns+0x125/0x760 net/core/net_namespace.c:459
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:227
 ksys_unshare+0x445/0x920 kernel/fork.c:3183
 __do_sys_unshare kernel/fork.c:3254 [inline]
 __se_sys_unshare kernel/fork.c:3252 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3252
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff888045e90000
 which belongs to the cache net_namespace of size 6784
The buggy address is located 704 bytes inside of
 6784-byte region [ffff888045e90000, ffff888045e91a80)

The buggy address belongs to the physical page:
page:ffffea000117a400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x45e90
head:ffffea000117a400 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff888025f88481
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0001eef800 dead000000000003 ffff8881400073c0
raw: 0000000000000000 0000000080040004 00000001ffffffff ffff888025f88481
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3643, tgid 3643 (syz-executor.0), ts 139548437774, free_ts 11319777265
 prep_new_page mm/page_alloc.c:2532 [inline]
 get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283
 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515
 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:1824 [inline]
 allocate_slab+0x27e/0x3d0 mm/slub.c:1969
 new_slab mm/slub.c:2029 [inline]
 ___slab_alloc+0x7f1/0xe10 mm/slub.c:3031
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118
 slab_alloc_node mm/slub.c:3209 [inline]
 slab_alloc mm/slub.c:3251 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3258 [inline]
 kmem_cache_alloc+0x38c/0x3b0 mm/slub.c:3268
 kmem_cache_zalloc include/linux/slab.h:723 [inline]
 net_alloc net/core/net_namespace.c:404 [inline]
 copy_net_ns+0x125/0x760 net/core/net_namespace.c:459
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:227
 ksys_unshare+0x445/0x920 kernel/fork.c:3183
 __do_sys_unshare kernel/fork.c:3254 [inline]
 __se_sys_unshare kernel/fork.c:3252 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3252
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1449 [inline]
 free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499
 free_unref_page_prepare mm/page_alloc.c:3380 [inline]
 free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476
 free_contig_range+0xb1/0x180 mm/page_alloc.c:9408
 destroy_args+0xa8/0x646 mm/debug_vm_pgtable.c:1031
 debug_vm_pgtable+0x2945/0x29d6 mm/debug_vm_pgtable.c:1354
 do_one_initcall+0xfe/0x650 init/main.c:1296
 do_initcall_level init/main.c:1369 [inline]
 do_initcalls init/main.c:1385 [inline]
 do_basic_setup init/main.c:1404 [inline]
 kernel_init_freeable+0x6b1/0x73a init/main.c:1611
 kernel_init+0x1a/0x1d0 init/main.c:1500
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

Memory state around the buggy address:
 ffff888045e90180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888045e90200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888045e90280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888045e90300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888045e90380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	fc                   	cld
   1:	a2 7e 83 f8 01 0f 85 	movabs %al,0x2e8850f01f8837e
   8:	e8 02
   a:	00 00                	add    %al,(%rax)
   c:	9c                   	pushfq
   d:	58                   	pop    %rax
   e:	f6 c4 02             	test   $0x2,%ah
  11:	0f 85 fb 02 00 00    	jne    0x312
  17:	48 83 7c 24 08 00    	cmpq   $0x0,0x8(%rsp)
  1d:	74 01                	je     0x20
  1f:	fb                   	sti
  20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  27:	fc ff df
* 2a:	48 01 c3             	add    %rax,%rbx <-- trapping instruction
  2d:	48 c7 03 00 00 00 00 	movq   $0x0,(%rbx)
  34:	48 c7 43 08 00 00 00 	movq   $0x0,0x8(%rbx)
  3b:	00
  3c:	48                   	rex.W
  3d:	8b                   	.byte 0x8b
  3e:	84                   	.byte 0x84
  3f:	24                   	.byte 0x24