==================================================================
BUG: KASAN: use-after-free in tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515
Read of size 8 at addr ffff88807eceb6d8 by task syz-executor.0/5866

CPU: 1 PID: 5866 Comm: syz-executor.0 Not tainted 5.15.110-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515
 tcp_write_timer_handler+0x1f7/0x9c0 net/ipv4/tcp_timer.c:626
 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:646
 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421
 expire_timers kernel/time/timer.c:1466 [inline]
 __run_timers+0x67c/0x890 kernel/time/timer.c:1737
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750
 __do_softirq+0x3b3/0x93a kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x155/0x240 kernel/softirq.c:636
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__preempt_count_add kernel/rcu/tree.c:1117 [inline]
RIP: 0010:rcu_is_watching+0x4/0xa0 kernel/rcu/tree.c:1120
Code: 5d 41 5e 41 5f 5d c3 e8 7a 68 af 08 41 f7 c4 00 02 00 00 75 b4 eb b3 e8 5a 68 af 08 66 2e 0f 1f 84 00 00 00 00 00 41 57 41 56 <53> 65 ff 05 8c af 97 7e e8 ff 7b af 08 89 c3 83 f8 08 73 72 49 bf
RSP: 0018:ffffc9000423f728 EFLAGS: 00000202
RAX: 0000000000000002 RBX: 0000000000000001 RCX: ffff88804e3f1d00
RDX: ffff88804e3f1d00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000423f850 R08: ffffffff88bb2c4e R09: fffffbfff1f78c21
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88814b4f5f40
R13: 1ffffffff1b77558 R14: ffffffff917bb2c0 R15: dffffc0000000000
 rcu_read_lock include/linux/rcupdate.h:697 [inline]
 inet_twsk_purge+0x137/0xa20 net/ipv4/inet_timewait_sock.c:268
 ops_exit_list net/core/net_namespace.c:174 [inline]
 setup_net+0x81c/0x9e0 net/core/net_namespace.c:352
 copy_net_ns+0x395/0x5d0 net/core/net_namespace.c:473
 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110
 copy_namespaces+0x365/0x3b0 kernel/nsproxy.c:178
 copy_process+0x1841/0x3ef0 kernel/fork.c:2201
 kernel_clone+0x210/0x960 kernel/fork.c:2601
 __do_sys_clone kernel/fork.c:2718 [inline]
 __se_sys_clone kernel/fork.c:2702 [inline]
 __x64_sys_clone+0x23f/0x290 kernel/fork.c:2702
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fb91e2cd169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb91c83f118 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fb91e3ecf80 RCX: 00007fb91e2cd169
RDX: 0000000000000000 RSI: 0000553a21e21000 RDI: 00000000c0800400
RBP: 00007fb91e328ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ffd7d9dc59f R14: 00007fb91c83f300 R15: 0000000000022000
 </TASK>

Allocated by task 3530:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x53/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 net_alloc net/core/net_namespace.c:405 [inline]
 copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:460
 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226
 ksys_unshare+0x580/0xb20 kernel/fork.c:3094
 __do_sys_unshare kernel/fork.c:3168 [inline]
 __se_sys_unshare kernel/fork.c:3166 [inline]
 __x64_sys_unshare+0x34/0x40 kernel/fork.c:3166
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 495:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x80 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kmem_cache_free+0x91/0x1f0 mm/slub.c:3515
 net_free net/core/net_namespace.c:434 [inline]
 cleanup_net+0xab5/0xb60 net/core/net_namespace.c:617
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2306
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2453
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

The buggy address belongs to the object at ffff88807eceb480
 which belongs to the cache net_namespace of size 6464
The buggy address is located 600 bytes inside of
 6464-byte region [ffff88807eceb480, ffff88807ececdc0)
The buggy address belongs to the page:
page:ffffea0001fb3a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807ececec0 pfn:0x7ece8
head:ffffea0001fb3a00 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff88807559c001
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888011dc63c0
raw: ffff88807ececec0 0000000080040003 00000001ffffffff ffff88807559c001
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 3517, ts 81037410872, free_ts 81036958178
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421
 alloc_slab_page mm/slub.c:1775 [inline]
 allocate_slab mm/slub.c:1912 [inline]
 new_slab+0xbb/0x4b0 mm/slub.c:1975
 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x18e/0x280 mm/slub.c:3233
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 net_alloc net/core/net_namespace.c:405 [inline]
 copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:460
 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226
 ksys_unshare+0x580/0xb20 kernel/fork.c:3094
 __do_sys_unshare kernel/fork.c:3168 [inline]
 __se_sys_unshare kernel/fork.c:3166 [inline]
 __x64_sys_unshare+0x34/0x40 kernel/fork.c:3166
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396
 free_nonslab_page+0xe4/0x150 mm/slub.c:3535
 kfree+0x1cf/0x270 mm/slub.c:4556
 skb_free_head net/core/skbuff.c:655 [inline]
 skb_release_data+0x73a/0x8a0 net/core/skbuff.c:677
 skb_release_all net/core/skbuff.c:742 [inline]
 __kfree_skb net/core/skbuff.c:756 [inline]
 consume_skb+0xa3/0x140 net/core/skbuff.c:914
 skb_free_datagram+0x24/0xe0 net/core/datagram.c:325
 netlink_recvmsg+0x5ef/0x1140 net/netlink/af_netlink.c:2030
 ____sys_recvmsg+0x286/0x530
 ___sys_recvmsg+0x1ec/0x690 net/socket.c:2673
 __sys_recvmsg net/socket.c:2703 [inline]
 __do_sys_recvmsg net/socket.c:2713 [inline]
 __se_sys_recvmsg net/socket.c:2710 [inline]
 __x64_sys_recvmsg+0x1dc/0x2b0 net/socket.c:2710
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Memory state around the buggy address:
 ffff88807eceb580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807eceb600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807eceb680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff88807eceb700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807eceb780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	5d                   	pop    %rbp
   1:	41 5e                	pop    %r14
   3:	41 5f                	pop    %r15
   5:	5d                   	pop    %rbp
   6:	c3                   	retq
   7:	e8 7a 68 af 08       	callq  0x8af6886
   c:	41 f7 c4 00 02 00 00 	test   $0x200,%r12d
  13:	75 b4                	jne    0xffffffc9
  15:	eb b3                	jmp    0xffffffca
  17:	e8 5a 68 af 08       	callq  0x8af6876
  1c:	66 2e 0f 1f 84 00 00 	nopw   %cs:0x0(%rax,%rax,1)
  23:	00 00 00
  26:	41 57                	push   %r15
  28:	41 56                	push   %r14
* 2a:	53                   	push   %rbx <-- trapping instruction
  2b:	65 ff 05 8c af 97 7e 	incl   %gs:0x7e97af8c(%rip)        # 0x7e97afbe
  32:	e8 ff 7b af 08       	callq  0x8af7c36
  37:	89 c3                	mov    %eax,%ebx
  39:	83 f8 08             	cmp    $0x8,%eax
  3c:	73 72                	jae    0xb0
  3e:	49                   	rex.WB
  3f:	bf                   	.byte 0xbf