==================================================================
BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:388 [inline]
BUG: KASAN: use-after-free in tcp_write_timer_handler+0x7ef/0x930 net/ipv4/tcp_timer.c:652
Read of size 1 at addr ffff88807788dc05 by task syz-executor.4/27421

CPU: 0 PID: 27421 Comm: syz-executor.4 Not tainted 6.1.83-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x15f/0x4f0 mm/kasan/report.c:395
 kasan_report+0x136/0x160 mm/kasan/report.c:495
 tcp_probe_timer net/ipv4/tcp_timer.c:388 [inline]
 tcp_write_timer_handler+0x7ef/0x930 net/ipv4/tcp_timer.c:652
 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:665
 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1519 [inline]
 __run_timers+0x67c/0x890 kernel/time/timer.c:1790
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803
 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x155/0x240 kernel/softirq.c:650
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:batadv_check_known_mac_addr+0x135/0x400 net/batman-adv/hard-interface.c:514
Code: 00 00 4c 89 f8 48 c1 e8 03 48 89 44 24 20 49 c7 c6 e0 81 0f 92 4c 89 7c 24 08 48 8d 6b 10 48 89 e8 48 c1 e8 03 42 0f b6 04 28 <84> c0 0f 85 7b 01 00 00 0f b6 45 00 04 fd 0f b6 e8 bf 02 00 00 00
RSP: 0018:ffffc900052e72c8 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffff888076717800 RCX: 0000000000040000
RDX: ffffc9000506a000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffff888076717810 R08: ffffffff8a597ec2 R09: fffffbfff2092e45
R10: 0000000000000000 R11: dffffc0000000001 R12: 00000000aaaabeaa
R13: dffffc0000000000 R14: ffffffff920f81e0 R15: ffff888014282380
 batadv_hardif_add_interface net/batman-adv/hard-interface.c:900 [inline]
 batadv_hard_if_event+0x1078/0x1540 net/batman-adv/hard-interface.c:964
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:455
 call_netdevice_notifiers_info net/core/dev.c:1970 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2008 [inline]
 call_netdevice_notifiers+0x145/0x1b0 net/core/dev.c:2022
 register_netdevice+0x12f2/0x1720 net/core/dev.c:10132
 __ip_tunnel_create+0x2b0/0x370 net/ipv4/ip_tunnel.c:267
 ip_tunnel_init_net+0x21f/0x700 net/ipv4/ip_tunnel.c:1100
 ops_init+0x356/0x600 net/core/net_namespace.c:135
 setup_net+0x4b5/0xb90 net/core/net_namespace.c:332
 copy_net_ns+0x395/0x5d0 net/core/net_namespace.c:478
 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110
 copy_namespaces+0x397/0x3f0 kernel/nsproxy.c:178
 copy_process+0x1ab8/0x4060 kernel/fork.c:2270
 kernel_clone+0x222/0x920 kernel/fork.c:2682
 __do_sys_clone kernel/fork.c:2823 [inline]
 __se_sys_clone kernel/fork.c:2807 [inline]
 __x64_sys_clone+0x231/0x280 kernel/fork.c:2807
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fd881a7dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd882817078 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fd881babf80 RCX: 00007fd881a7dda9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000660694c0
RBP: 00007fd881aca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 000000000000000b R14: 00007fd881babf80 R15: 00007ffef9ec2488
 </TASK>

Allocated by task 3565:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737
 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+0x10c/0x2d0 mm/slub.c:3422
 kmem_cache_zalloc include/linux/slab.h:682 [inline]
 net_alloc net/core/net_namespace.c:410 [inline]
 copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:465
 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:3203
 __do_sys_unshare kernel/fork.c:3274 [inline]
 __se_sys_unshare kernel/fork.c:3272 [inline]
 __x64_sys_unshare+0x34/0x40 kernel/fork.c:3272
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Last potentially related work creation:
 kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486
 insert_work+0x54/0x3d0 kernel/workqueue.c:1361
 __queue_work+0xb4b/0xf90 kernel/workqueue.c:1520
 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1514 [inline]
 __run_timers+0x6a8/0x890 kernel/time/timer.c:1790
 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571

Second to last potentially related work creation:
 kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486
 insert_work+0x54/0x3d0 kernel/workqueue.c:1361
 __queue_work+0xb4b/0xf90 kernel/workqueue.c:1520
 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1514 [inline]
 __run_timers+0x6a8/0x890 kernel/time/timer.c:1790
 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571

The buggy address belongs to the object at ffff88807788d4c0
 which belongs to the cache net_namespace of size 6976
The buggy address is located 1861 bytes inside of
 6976-byte region [ffff88807788d4c0, ffff88807788f000)

The buggy address belongs to the physical page:
page:ffffea0001de2200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807788d4c0 pfn:0x77888
head:ffffea0001de2200 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888140009500
raw: ffff88807788d4c0 0000000080040001 00000001ffffffff 0000000000000000
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 3572, tgid 3572 (syz-executor.4), ts 60560247038, free_ts 60559132085
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2513
 prep_new_page mm/page_alloc.c:2520 [inline]
 get_page_from_freelist+0x31a1/0x3320 mm/page_alloc.c:4279
 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5545
 alloc_slab_page+0x6a/0x150 mm/slub.c:1794
 allocate_slab mm/slub.c:1939 [inline]
 new_slab+0x84/0x2d0 mm/slub.c:1992
 ___slab_alloc+0xc20/0x1270 mm/slub.c:3180
 __slab_alloc mm/slub.c:3279 [inline]
 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+0x1a5/0x2d0 mm/slub.c:3422
 kmem_cache_zalloc include/linux/slab.h:682 [inline]
 net_alloc net/core/net_namespace.c:410 [inline]
 copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:465
 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:3203
 __do_sys_unshare kernel/fork.c:3274 [inline]
 __se_sys_unshare kernel/fork.c:3272 [inline]
 __x64_sys_unshare+0x34/0x40 kernel/fork.c:3272
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 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:1440 [inline]
 free_pcp_prepare mm/page_alloc.c:1490 [inline]
 free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3358
 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3453
 free_slab mm/slub.c:2031 [inline]
 discard_slab mm/slub.c:2037 [inline]
 __unfreeze_partials+0x1b7/0x210 mm/slub.c:2586
 put_cpu_partial+0x17b/0x250 mm/slub.c:2662
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x156/0x170 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x1f/0x70 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737
 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_lru+0x10c/0x2d0 mm/slub.c:3429
 alloc_inode_sb include/linux/fs.h:3193 [inline]
 sock_alloc_inode+0x24/0xc0 net/socket.c:306
 alloc_inode fs/inode.c:261 [inline]
 new_inode_pseudo+0x61/0x1d0 fs/inode.c:1020
 sock_alloc net/socket.c:631 [inline]
 __sock_create+0x11f/0x910 net/socket.c:1514
 sock_create net/socket.c:1601 [inline]
 __sys_socket_create net/socket.c:1638 [inline]
 __sys_socket+0x136/0x3a0 net/socket.c:1666
 __do_sys_socket net/socket.c:1679 [inline]
 __se_sys_socket net/socket.c:1677 [inline]
 __x64_sys_socket+0x76/0x80 net/socket.c:1677
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff88807788db00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807788db80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807788dc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88807788dc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807788dd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	4c 89 f8             	mov    %r15,%rax
   5:	48 c1 e8 03          	shr    $0x3,%rax
   9:	48 89 44 24 20       	mov    %rax,0x20(%rsp)
   e:	49 c7 c6 e0 81 0f 92 	mov    $0xffffffff920f81e0,%r14
  15:	4c 89 7c 24 08       	mov    %r15,0x8(%rsp)
  1a:	48 8d 6b 10          	lea    0x10(%rbx),%rbp
  1e:	48 89 e8             	mov    %rbp,%rax
  21:	48 c1 e8 03          	shr    $0x3,%rax
  25:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax
* 2a:	84 c0                	test   %al,%al <-- trapping instruction
  2c:	0f 85 7b 01 00 00    	jne    0x1ad
  32:	0f b6 45 00          	movzbl 0x0(%rbp),%eax
  36:	04 fd                	add    $0xfd,%al
  38:	0f b6 e8             	movzbl %al,%ebp
  3b:	bf 02 00 00 00       	mov    $0x2,%edi