==================================================================
BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2f87/0x3400 net/ipv4/tcp_timer.c:509
Read of size 8 at addr ffff88804a92bb40 by task swapper/1/0

CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.1.0-rc1-syzkaller-00115-g0bda03623e6b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
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:284 [inline]
 print_report+0x15e/0x45d mm/kasan/report.c:395
 kasan_report+0xbb/0x1f0 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+0x1da/0x7c0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1519 [inline]
 __run_timers.part.0+0x6a2/0xaf0 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+0x1f7/0xad8 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:1107
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline]
RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:113 [inline]
RIP: 0010:acpi_idle_do_entry+0x1fd/0x2a0 drivers/acpi/processor_idle.c:572
Code: 89 de e8 e6 46 eb f7 84 db 75 ac e8 4d 4a eb f7 e8 08 c1 f1 f7 66 90 e8 41 4a eb f7 0f 00 2d 4a 57 c3 00 e8 35 4a eb f7 fb f4 <9c> 5b 81 e3 00 02 00 00 fa 31 ff 48 89 de e8 10 47 eb f7 48 85 db
RSP: 0018:ffffc90000177d10 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888011a81d40 RSI: ffffffff899140bb RDI: ffffffff899140a8
RBP: ffff888017cb9864 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001
R13: ffff888017cb9800 R14: ffff888017cb9864 R15: ffff8881468fe804
 acpi_idle_enter+0x364/0x500 drivers/acpi/processor_idle.c:709
 cpuidle_enter_state+0x1ab/0xd30 drivers/cpuidle/cpuidle.c:239
 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:356
 call_cpuidle kernel/sched/idle.c:155 [inline]
 cpuidle_idle_call kernel/sched/idle.c:236 [inline]
 do_idle+0x3f7/0x590 kernel/sched/idle.c:303
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:400
 start_secondary+0x252/0x300 arch/x86/kernel/smpboot.c:262
 secondary_startup_64_no_verify+0xce/0xdb
 </TASK>

Allocated by task 4087:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45
 kasan_set_track+0x21/0x30 mm/kasan/common.c:52
 __kasan_slab_alloc+0x7e/0x80 mm/kasan/common.c:325
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slab.h:737 [inline]
 slab_alloc_node mm/slub.c:3398 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc+0x2ac/0x3c0 mm/slub.c:3422
 kmem_cache_zalloc include/linux/slab.h:702 [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:3188
 __do_sys_unshare kernel/fork.c:3259 [inline]
 __se_sys_unshare kernel/fork.c:3257 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3257
 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

Last potentially related work creation:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:481
 insert_work+0x48/0x350 kernel/workqueue.c:1358
 __queue_work+0x693/0x13b0 kernel/workqueue.c:1517
 call_timer_fn+0x1da/0x7c0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1514 [inline]
 __run_timers.part.0+0x4a3/0xaf0 kernel/time/timer.c:1790
 __run_timers kernel/time/timer.c:1768 [inline]
 run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1805
 __do_softirq+0x1f7/0xad8 kernel/softirq.c:571

Second to last potentially related work creation:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:481
 insert_work+0x48/0x350 kernel/workqueue.c:1358
 __queue_work+0x693/0x13b0 kernel/workqueue.c:1517
 call_timer_fn+0x1da/0x7c0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1514 [inline]
 __run_timers.part.0+0x4a3/0xaf0 kernel/time/timer.c:1790
 __run_timers kernel/time/timer.c:1768 [inline]
 run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1805
 __do_softirq+0x1f7/0xad8 kernel/softirq.c:571

The buggy address belongs to the object at ffff88804a92b880
 which belongs to the cache net_namespace of size 6976
The buggy address is located 704 bytes inside of
 6976-byte region [ffff88804a92b880, ffff88804a92d3c0)

The buggy address belongs to the physical page:
page:ffffea00012a4a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88804a92b880 pfn:0x4a928
head:ffffea00012a4a00 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff88807993e041
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0001679c08 ffffea00017b4c08 ffff8880119d6500
raw: ffff88804a92b880 0000000000040002 00000001ffffffff ffff88807993e041
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 3634, tgid 3634 (syz-executor.0), ts 116364535123, free_ts 11967964581
 prep_new_page mm/page_alloc.c:2538 [inline]
 get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4287
 __alloc_pages+0x1c7/0x5a0 mm/page_alloc.c:5554
 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2280
 alloc_slab_page mm/slub.c:1794 [inline]
 allocate_slab+0x213/0x300 mm/slub.c:1939
 new_slab mm/slub.c:1992 [inline]
 ___slab_alloc+0xa91/0x1400 mm/slub.c:3180
 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279
 slab_alloc_node mm/slub.c:3364 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc+0x312/0x3c0 mm/slub.c:3422
 kmem_cache_zalloc include/linux/slab.h:702 [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:3188
 __do_sys_unshare kernel/fork.c:3259 [inline]
 __se_sys_unshare kernel/fork.c:3257 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3257
 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:1458 [inline]
 free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1508
 free_unref_page_prepare mm/page_alloc.c:3386 [inline]
 free_unref_page+0x19/0x4d0 mm/page_alloc.c:3482
 free_contig_range+0xb1/0x180 mm/page_alloc.c:9488
 destroy_args+0xa8/0x64c mm/debug_vm_pgtable.c:1031
 debug_vm_pgtable+0x2954/0x29e5 mm/debug_vm_pgtable.c:1354
 do_one_initcall+0x13d/0x780 init/main.c:1303
 do_initcall_level init/main.c:1376 [inline]
 do_initcalls init/main.c:1392 [inline]
 do_basic_setup init/main.c:1411 [inline]
 kernel_init_freeable+0x6ff/0x788 init/main.c:1631
 kernel_init+0x1a/0x1d0 init/main.c:1519
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

Memory state around the buggy address:
 ffff88804a92ba00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804a92ba80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88804a92bb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff88804a92bb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804a92bc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	89 de                	mov    %ebx,%esi
   2:	e8 e6 46 eb f7       	callq  0xf7eb46ed
   7:	84 db                	test   %bl,%bl
   9:	75 ac                	jne    0xffffffb7
   b:	e8 4d 4a eb f7       	callq  0xf7eb4a5d
  10:	e8 08 c1 f1 f7       	callq  0xf7f1c11d
  15:	66 90                	xchg   %ax,%ax
  17:	e8 41 4a eb f7       	callq  0xf7eb4a5d
  1c:	0f 00 2d 4a 57 c3 00 	verw   0xc3574a(%rip)        # 0xc3576d
  23:	e8 35 4a eb f7       	callq  0xf7eb4a5d
  28:	fb                   	sti
  29:	f4                   	hlt
* 2a:	9c                   	pushfq <-- trapping instruction
  2b:	5b                   	pop    %rbx
  2c:	81 e3 00 02 00 00    	and    $0x200,%ebx
  32:	fa                   	cli
  33:	31 ff                	xor    %edi,%edi
  35:	48 89 de             	mov    %rbx,%rsi
  38:	e8 10 47 eb f7       	callq  0xf7eb474d
  3d:	48 85 db             	test   %rbx,%rbx