Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable
==================================================================
BUG: KASAN: stack-out-of-bounds in string_nocheck lib/vsprintf.c:645 [inline]
BUG: KASAN: stack-out-of-bounds in string+0x394/0x3d0 lib/vsprintf.c:727
Read of size 1 at addr ffffc90011d573f5 by task syz-executor.5/29056

CPU: 1 PID: 29056 Comm: syz-executor.5 Not tainted 6.6.0-syzkaller-05843-g89ed67ef126c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xc4/0x620 mm/kasan/report.c:475
 kasan_report+0xda/0x110 mm/kasan/report.c:588
 string_nocheck lib/vsprintf.c:645 [inline]
 string+0x394/0x3d0 lib/vsprintf.c:727
 vsnprintf+0xc5f/0x1870 lib/vsprintf.c:2818
 vprintk_store+0x3a0/0xb80 kernel/printk/printk.c:2191
 vprintk_emit+0x14c/0x5f0 kernel/printk/printk.c:2288
 vprintk+0x7b/0x90 kernel/printk/printk_safe.c:45
 _printk+0xc8/0x100 kernel/printk/printk.c:2332
 tcp_inbound_hash.constprop.0+0xdb2/0x10d0 include/net/tcp.h:2760
 tcp_v6_rcv+0x2b31/0x34d0 net/ipv6/tcp_ipv6.c:1882
 ip6_protocol_deliver_rcu+0x33b/0x13d0 net/ipv6/ip6_input.c:438
 ip6_input_finish+0x14f/0x2f0 net/ipv6/ip6_input.c:483
 NF_HOOK include/linux/netfilter.h:314 [inline]
 NF_HOOK include/linux/netfilter.h:308 [inline]
 ip6_input+0xce/0x440 net/ipv6/ip6_input.c:492
 dst_input include/net/dst.h:461 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline]
 NF_HOOK include/linux/netfilter.h:314 [inline]
 NF_HOOK include/linux/netfilter.h:308 [inline]
 ipv6_rcv+0x563/0x720 net/ipv6/ip6_input.c:310
 __netif_receive_skb_one_core+0x115/0x180 net/core/dev.c:5527
 __netif_receive_skb+0x1f/0x1b0 net/core/dev.c:5641
 netif_receive_skb_internal net/core/dev.c:5727 [inline]
 netif_receive_skb+0x133/0x700 net/core/dev.c:5786
 tun_rx_batched+0x429/0x780 drivers/net/tun.c:1579
 tun_get_user+0x29e3/0x3bc0 drivers/net/tun.c:2002
 tun_chr_write_iter+0xe8/0x210 drivers/net/tun.c:2048
 call_write_iter include/linux/fs.h:2020 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x64f/0xdf0 fs/read_write.c:584
 ksys_write+0x12f/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f8a6627b82f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 b9 80 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 0c 81 02 00 48
RSP: 002b:00007f8a67009090 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f8a6639bf80 RCX: 00007f8a6627b82f
RDX: 000000000000008a RSI: 00000000200001c0 RDI: 00000000000000c8
RBP: 00007f8a662c847a R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000008a R11: 0000000000000293 R12: 0000000000000000
R13: 000000000000000b R14: 00007f8a6639bf80 R15: 00007f8a664bfa48
 </TASK>

The buggy address belongs to stack of task syz-executor.5/29056
 and is located at offset 101 in frame:
 tcp_inbound_hash.constprop.0+0x0/0x10d0 include/net/net_namespace.h:385

This frame has 3 objects:
 [32, 40) 'md5_tmp'
 [64, 72) 'ao_tmp'
 [96, 101) 'hdr_flags'

The buggy address belongs to the virtual mapping at
 [ffffc90011d50000, ffffc90011d59000) created by:
 kernel_clone+0xfd/0x920 kernel/fork.c:2907

The buggy address belongs to the physical page:
page:ffffea0000a1dd00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28774
memcg:ffff888020df1e02
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff888020df1e02
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 5105, tgid 5105 (syz-executor.0), ts 1446587277205, free_ts 1446529536561
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536
 prep_new_page mm/page_alloc.c:1543 [inline]
 get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170
 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4426
 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2303
 vm_area_alloc_pages mm/vmalloc.c:3063 [inline]
 __vmalloc_area_node mm/vmalloc.c:3139 [inline]
 __vmalloc_node_range+0x8f3/0x1bf0 mm/vmalloc.c:3320
 alloc_thread_stack_node kernel/fork.c:309 [inline]
 dup_task_struct kernel/fork.c:1118 [inline]
 copy_process+0x13e3/0x73f0 kernel/fork.c:2325
 kernel_clone+0xfd/0x920 kernel/fork.c:2907
 __do_sys_clone+0xba/0x100 kernel/fork.c:3050
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1136 [inline]
 free_unref_page_prepare+0x476/0xa40 mm/page_alloc.c:2312
 free_unref_page_list+0xe6/0xb30 mm/page_alloc.c:2451
 release_pages+0x32a/0x14e0 mm/swap.c:1042
 tlb_batch_pages_flush+0x9a/0x190 mm/mmu_gather.c:98
 tlb_flush_mmu_free mm/mmu_gather.c:293 [inline]
 tlb_flush_mmu mm/mmu_gather.c:300 [inline]
 tlb_finish_mmu+0x14b/0x6f0 mm/mmu_gather.c:392
 exit_mmap+0x38b/0xa60 mm/mmap.c:3237
 __mmput+0x12a/0x4d0 kernel/fork.c:1349
 mmput+0x62/0x70 kernel/fork.c:1371
 exit_mm kernel/exit.c:567 [inline]
 do_exit+0x9ad/0x2a20 kernel/exit.c:861
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1024
 get_signal+0x23ba/0x2790 kernel/signal.c:2915
 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296
 do_syscall_64+0x4b/0x110 arch/x86/entry/common.c:88
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Memory state around the buggy address:
 ffffc90011d57280: 00 f1 f1 f1 f1 00 00 00 f3 f3 f3 f3 f3 00 00 00
 ffffc90011d57300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90011d57380: 00 00 f1 f1 f1 f1 00 f2 f2 f2 00 f2 f2 f2 05 f3
                                                             ^
 ffffc90011d57400: f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90011d57480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================