==================================================================
BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:378 [inline]
BUG: KASAN: use-after-free in tcp_write_timer_handler net/ipv4/tcp_timer.c:624 [inline]
BUG: KASAN: use-after-free in tcp_write_timer_handler+0x998/0x9f0 net/ipv4/tcp_timer.c:594
Read of size 1 at addr ffff88807a3bdc05 by task syz-executor.0/17484

CPU: 1 PID: 17484 Comm: syz-executor.0 Not tainted 6.0.0-syzkaller-02734-g0326074ff465 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
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:317 [inline]
 print_report.cold+0x2ba/0x719 mm/kasan/report.c:433
 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495
 tcp_probe_timer net/ipv4/tcp_timer.c:378 [inline]
 tcp_write_timer_handler net/ipv4/tcp_timer.c:624 [inline]
 tcp_write_timer_handler+0x998/0x9f0 net/ipv4/tcp_timer.c:594
 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:637
 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1519 [inline]
 __run_timers.part.0+0x674/0xa80 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+0x1d0/0x9c8 kernel/softirq.c:571
 do_softirq.part.0+0xde/0x130 kernel/softirq.c:472
 </IRQ>
 <TASK>
 do_softirq kernel/softirq.c:464 [inline]
 __local_bh_enable_ip+0x102/0x120 kernel/softirq.c:396
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:808 [inline]
 ip_finish_output2+0x7d0/0x2170 net/ipv4/ip_output.c:229
 __ip_finish_output net/ipv4/ip_output.c:306 [inline]
 __ip_finish_output+0x396/0x650 net/ipv4/ip_output.c:288
 ip_finish_output+0x2d/0x280 net/ipv4/ip_output.c:316
 NF_HOOK_COND include/linux/netfilter.h:291 [inline]
 ip_mc_output+0x21b/0x700 net/ipv4/ip_output.c:415
 dst_output include/net/dst.h:445 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 ip_send_skb+0xd4/0x260 net/ipv4/ip_output.c:1586
 udp_send_skb+0x725/0x1430 net/ipv4/udp.c:971
 udp_sendmsg+0x1bb8/0x2740 net/ipv4/udp.c:1258
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 ____sys_sendmsg+0x334/0x8c0 net/socket.c:2482
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
 __sys_sendmmsg+0x18b/0x460 net/socket.c:2622
 __do_sys_sendmmsg net/socket.c:2651 [inline]
 __se_sys_sendmmsg net/socket.c:2648 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2648
 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
RIP: 0033:0x7f2160e8b5a9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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:00007f21620e7168 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f2160fabf80 RCX: 00007f2160e8b5a9
RDX: 04000000000001a8 RSI: 0000000020007fc0 RDI: 0000000000000006
RBP: 00007f2160ee6580 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff8d561a9f R14: 00007f21620e7300 R15: 0000000000022000
 </TASK>

Allocated by task 16688:
 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:437 [inline]
 __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:470
 kasan_slab_alloc include/linux/kasan.h:224 [inline]
 slab_post_alloc_hook mm/slab.h:727 [inline]
 slab_alloc_node mm/slub.c:3248 [inline]
 slab_alloc mm/slub.c:3256 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3263 [inline]
 kmem_cache_alloc+0x267/0x3b0 mm/slub.c:3273
 kmem_cache_zalloc include/linux/slab.h:723 [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:3181
 __do_sys_unshare kernel/fork.c:3252 [inline]
 __se_sys_unshare kernel/fork.c:3250 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3250
 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

The buggy address belongs to the object at ffff88807a3bd4c0
 which belongs to the cache net_namespace of size 6976
The buggy address is located 1861 bytes inside of
 6976-byte region [ffff88807a3bd4c0, ffff88807a3bf000)

The buggy address belongs to the physical page:
page:ffffea0001e8ee00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807a3b9c40 pfn:0x7a3b8
head:ffffea0001e8ee00 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff88807e9c2ec1
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea000198ae08 ffffea0001f14c08 ffff8880119d43c0
raw: ffff88807a3b9c40 0000000000040002 00000001ffffffff ffff88807e9c2ec1
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 3624, tgid 3624 (syz-executor.1), ts 84011097351, free_ts 84003060752
 prep_new_page mm/page_alloc.c:2532 [inline]
 get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283
 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5549
 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:1829 [inline]
 allocate_slab+0x27e/0x3d0 mm/slub.c:1974
 new_slab mm/slub.c:2034 [inline]
 ___slab_alloc+0x84f/0xe80 mm/slub.c:3036
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3123
 slab_alloc_node mm/slub.c:3214 [inline]
 slab_alloc mm/slub.c:3256 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3263 [inline]
 kmem_cache_alloc+0x38c/0x3b0 mm/slub.c:3273
 kmem_cache_zalloc include/linux/slab.h:723 [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:3181
 __do_sys_unshare kernel/fork.c:3252 [inline]
 __se_sys_unshare kernel/fork.c:3250 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3250
 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:1449 [inline]
 free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499
 free_unref_page_prepare mm/page_alloc.c:3380 [inline]
 free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476
 skb_free_head+0xac/0x110 net/core/skbuff.c:760
 skb_release_data+0x5f1/0x870 net/core/skbuff.c:789
 skb_release_all net/core/skbuff.c:854 [inline]
 __kfree_skb net/core/skbuff.c:868 [inline]
 consume_skb net/core/skbuff.c:1033 [inline]
 consume_skb+0xc2/0x160 net/core/skbuff.c:1027
 netlink_recvmsg+0x598/0xe50 net/netlink/af_netlink.c:1998
 sock_recvmsg_nosec net/socket.c:995 [inline]
 sock_recvmsg net/socket.c:1013 [inline]
 sock_recvmsg net/socket.c:1009 [inline]
 ____sys_recvmsg+0x2c7/0x600 net/socket.c:2701
 ___sys_recvmsg+0xf2/0x180 net/socket.c:2743
 __sys_recvmsg+0xf0/0x1c0 net/socket.c:2773
 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

Memory state around the buggy address:
 ffff88807a3bdb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807a3bdb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807a3bdc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88807a3bdc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807a3bdd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================