==================================================================
BUG: KASAN: use-after-free in tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515
Read of size 8 at addr ffff88807e6b0258 by task syz-executor.1/8201

CPU: 0 PID: 8201 Comm: syz-executor.1 Not tainted 5.15.111-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
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:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:unwind_next_frame+0x25d/0x1fa0 arch/x86/kernel/unwind_orc.c:448
Code: f9 eb 8e 48 39 c6 0f 83 7d 15 00 00 4b 8d 0c 40 48 8d 8c 09 68 d8 53 8e 48 39 c1 0f 87 68 15 00 00 45 39 e0 0f 84 89 01 00 00 <4a> 8d 3c a5 fc 6c ee 8d 45 29 e0 4a 8d 6c 87 fc 49 89 fc 48 39 fd
RSP: 0018:ffffc9000206f048 EFLAGS: 00000202
RAX: ffffffff8eebf98a RBX: ffffffff8f08b880 RCX: ffffffff8ec92be4
RDX: dffffc0000000000 RSI: ffffffff8ec92bde RDI: ffffffff8138489b
RBP: 0000000000072fbc R08: 0000000000138dea R09: ffffc9000206f1f0
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000138de9
R13: ffffffff882fbc14 R14: 0000000000096084 R15: ffffc9000206f100
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 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]
 __proc_create+0x419/0x9f0 fs/proc/generic.c:426
 proc_create_reg+0x8c/0x110 fs/proc/generic.c:553
 proc_create_net_single+0xb4/0x1a0 fs/proc/proc_net.c:203
 can_init_proc+0xa4/0x350 net/can/proc.c:442
 can_pernet_init+0x2ae/0x2c0 net/can/af_can.c:816
 ops_init+0x356/0x600 net/core/net_namespace.c:135
 setup_net+0x358/0x9e0 net/core/net_namespace.c:329
 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: 0033:0x7f1921a0e169
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:00007f191ff80118 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f1921b2df80 RCX: 00007f1921a0e169
RDX: 0000000000000000 RSI: 00000000ffffff00 RDI: 0000000075848400
RBP: 00007f1921a69ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ffd99737aff R14: 00007f191ff80300 R15: 0000000000022000
 </TASK>

Allocated by task 3539:
 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 893:
 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:2307
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2454
 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 ffff88807e6b0000
 which belongs to the cache net_namespace of size 6464
The buggy address is located 600 bytes inside of
 6464-byte region [ffff88807e6b0000, ffff88807e6b1940)
The buggy address belongs to the page:
page:ffffea0001f9ac00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807e6b4ec0 pfn:0x7e6b0
head:ffffea0001f9ac00 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff888022d22001
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffff888011dc7288 ffffea0001366808 ffff888011dc63c0
raw: ffff88807e6b4ec0 0000000000040002 00000001ffffffff ffff888022d22001
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 3539, ts 108551938699, free_ts 108551864537
 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_slab mm/slub.c:2015 [inline]
 discard_slab mm/slub.c:2021 [inline]
 __unfreeze_partials+0x1b7/0x210 mm/slub.c:2507
 put_cpu_partial+0x132/0x1a0 mm/slub.c:2587
 do_slab_free mm/slub.c:3487 [inline]
 ___cache_free+0xe3/0x100 mm/slub.c:3506
 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444
 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
 create_nsproxy kernel/nsproxy.c:56 [inline]
 create_new_namespaces+0x34/0x7a0 kernel/nsproxy.c:74
 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

Memory state around the buggy address:
 ffff88807e6b0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807e6b0180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807e6b0200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff88807e6b0280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807e6b0300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	f9                   	stc
   1:	eb 8e                	jmp    0xffffff91
   3:	48 39 c6             	cmp    %rax,%rsi
   6:	0f 83 7d 15 00 00    	jae    0x1589
   c:	4b 8d 0c 40          	lea    (%r8,%r8,2),%rcx
  10:	48 8d 8c 09 68 d8 53 	lea    -0x71ac2798(%rcx,%rcx,1),%rcx
  17:	8e
  18:	48 39 c1             	cmp    %rax,%rcx
  1b:	0f 87 68 15 00 00    	ja     0x1589
  21:	45 39 e0             	cmp    %r12d,%r8d
  24:	0f 84 89 01 00 00    	je     0x1b3
* 2a:	4a 8d 3c a5 fc 6c ee 	lea    -0x72119304(,%r12,4),%rdi <-- trapping instruction
  31:	8d
  32:	45 29 e0             	sub    %r12d,%r8d
  35:	4a 8d 6c 87 fc       	lea    -0x4(%rdi,%r8,4),%rbp
  3a:	49 89 fc             	mov    %rdi,%r12
  3d:	48 39 fd             	cmp    %rdi,%rbp