==================================================================
BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511
Read of size 8 at addr ffff888049455540 by task syz-executor.5/17935

CPU: 1 PID: 17935 Comm: syz-executor.5 Not tainted 5.18.0-rc3-syzkaller-01617-g7aa424e02a04 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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/0x495 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:wait_consider_task+0x99/0x3c50 kernel/exit.c:1292
Code: 28 00 00 00 48 89 84 24 f0 00 00 00 31 c0 e8 9e 2e 32 00 49 8d 8f 5c 05 00 00 48 89 c8 48 89 4c 24 10 48 c1 e8 03 0f b6 14 28 <48> 89 c8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 c2 1a 00 00 45
RSP: 0018:ffffc90002e1fb60 EFLAGS: 00000a03
RAX: 1ffff110049330ab RBX: 0000000000000000 RCX: ffff88802499855c
RDX: 0000000000000000 RSI: ffffffff8146fec2 RDI: ffffc90002e1fd18
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff8ba0a083
R10: ffffffff81473d38 R11: 0000000000000001 R12: dffffc0000000000
R13: ffff888016c20000 R14: 0000000000000004 R15: ffff888024998000
 do_wait_thread kernel/exit.c:1401 [inline]
 do_wait+0x6ca/0xce0 kernel/exit.c:1518
 kernel_wait4+0x14c/0x260 kernel/exit.c:1681
 __do_sys_wait4+0x13f/0x150 kernel/exit.c:1709
 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+0x44/0xae
RIP: 0033:0x7f298fe87587
Code: 89 7c 24 10 48 89 4c 24 18 e8 35 50 02 00 4c 8b 54 24 18 8b 54 24 14 41 89 c0 48 8b 74 24 08 8b 7c 24 10 b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 89 44 24 10 e8 65 50 02 00 8b 44
RSP: 002b:00007ffe97fb7160 EFLAGS: 00000293 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 000000000000008e RCX: 00007f298fe87587
RDX: 0000000040000001 RSI: 00007ffe97fb71ec RDI: 00000000ffffffff
RBP: 00007ffe97fb71ec R08: 0000000000000000 R09: 00007ffe97fe8080
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032
R13: 0000000000139961 R14: 0000000000000005 R15: 00007ffe97fb7250
 </TASK>

Allocated by task 12638:
 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+0x90/0xc0 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_node mm/slub.c:3217 [inline]
 slab_alloc mm/slub.c:3225 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3232 [inline]
 kmem_cache_alloc+0x204/0x3b0 mm/slub.c:3242
 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+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 3713:
 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+0x166/0x1a0 mm/kasan/common.c:328
 kasan_slab_free include/linux/kasan.h:200 [inline]
 slab_free_hook mm/slub.c:1728 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754
 slab_free mm/slub.c:3510 [inline]
 kmem_cache_free+0xdd/0x5a0 mm/slub.c:3527
 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+0xbe/0xd0 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+0xbe/0xd0 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 ffff888049455280
 which belongs to the cache net_namespace of size 6784
The buggy address is located 704 bytes inside of
 6784-byte region [ffff888049455280, ffff888049456d00)

The buggy address belongs to the physical page:
page:ffffea0001251400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888049453700 pfn:0x49450
head:ffffea0001251400 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff888075f94681
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0001dc1000 dead000000000002 ffff888010dcd3c0
raw: ffff888049453700 0000000080040001 00000001ffffffff ffff888075f94681
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4886, tgid 4885 (syz-executor.0), ts 121051755819, free_ts 119500786706
 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+0x1aa/0x310 mm/mempolicy.c:2272
 alloc_slab_page mm/slub.c:1799 [inline]
 allocate_slab+0x26c/0x3c0 mm/slub.c:1944
 new_slab mm/slub.c:2004 [inline]
 ___slab_alloc+0x8df/0xf20 mm/slub.c:3005
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3092
 slab_alloc_node mm/slub.c:3183 [inline]
 slab_alloc mm/slub.c:3225 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3232 [inline]
 kmem_cache_alloc+0x360/0x3b0 mm/slub.c:3242
 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
 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178
 copy_process+0x2f79/0x6fe0 kernel/fork.c:2237
 kernel_clone+0xe7/0xab0 kernel/fork.c:2639
 __do_sys_clone+0xc8/0x110 kernel/fork.c:2756
 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+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
 __put_page+0x17d/0x280 mm/swap.c:127
 folio_put include/linux/mm.h:1200 [inline]
 put_page include/linux/mm.h:1233 [inline]
 __skb_frag_unref include/linux/skbuff.h:3370 [inline]
 skb_release_data+0x513/0x810 net/core/skbuff.c:672
 skb_release_all net/core/skbuff.c:742 [inline]
 __kfree_skb net/core/skbuff.c:756 [inline]
 kfree_skb_reason.part.0+0xc3/0x2f0 net/core/skbuff.c:776
 kfree_skb_reason+0x85/0x110 include/linux/refcount.h:279
 kfree_skb_list_reason net/core/skbuff.c:786 [inline]
 kfree_skb_list include/linux/skbuff.h:1300 [inline]
 skb_release_data+0x6aa/0x810 net/core/skbuff.c:675
 skb_release_all net/core/skbuff.c:742 [inline]
 __kfree_skb net/core/skbuff.c:756 [inline]
 kfree_skb_reason.part.0+0xc3/0x2f0 net/core/skbuff.c:776
 kfree_skb_reason+0x85/0x110 include/linux/refcount.h:279
 kfree_skb include/linux/skbuff.h:1289 [inline]
 kcm_sendmsg+0xe03/0x2420 net/kcm/kcmsock.c:1071
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 ____sys_sendmsg+0x6e2/0x800 net/socket.c:2413
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496
 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+0x44/0xae

Memory state around the buggy address:
 ffff888049455400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888049455480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888049455500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888049455580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888049455600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	28 00                	sub    %al,(%rax)
   2:	00 00                	add    %al,(%rax)
   4:	48 89 84 24 f0 00 00 	mov    %rax,0xf0(%rsp)
   b:	00
   c:	31 c0                	xor    %eax,%eax
   e:	e8 9e 2e 32 00       	callq  0x322eb1
  13:	49 8d 8f 5c 05 00 00 	lea    0x55c(%r15),%rcx
  1a:	48 89 c8             	mov    %rcx,%rax
  1d:	48 89 4c 24 10       	mov    %rcx,0x10(%rsp)
  22:	48 c1 e8 03          	shr    $0x3,%rax
  26:	0f b6 14 28          	movzbl (%rax,%rbp,1),%edx
* 2a:	48 89 c8             	mov    %rcx,%rax <-- trapping instruction
  2d:	83 e0 07             	and    $0x7,%eax
  30:	83 c0 03             	add    $0x3,%eax
  33:	38 d0                	cmp    %dl,%al
  35:	7c 08                	jl     0x3f
  37:	84 d2                	test   %dl,%dl
  39:	0f 85 c2 1a 00 00    	jne    0x1b01
  3f:	45                   	rex.RB