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BUG: KASAN: stack-out-of-bounds in ip6mr_ioctl+0xba3/0xcb0 net/ipv6/ip6mr.c:1917
Read of size 16 at addr ffffc900050cfb68 by task syz-executor.0/26984

CPU: 0 PID: 26984 Comm: syz-executor.0 Not tainted 6.4.0-rc6-syzkaller-01311-gb650d953cd39 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351
 print_report mm/kasan/report.c:462 [inline]
 kasan_report+0x11c/0x130 mm/kasan/report.c:572
 ip6mr_ioctl+0xba3/0xcb0 net/ipv6/ip6mr.c:1917
 rawv6_ioctl+0x4e/0x1e0 net/ipv6/raw.c:1143
 sock_ioctl_out net/core/sock.c:4186 [inline]
 sk_ioctl+0x151/0x440 net/core/sock.c:4214
 inet6_ioctl+0x1b8/0x290 net/ipv6/af_inet6.c:582
 sock_do_ioctl+0xcc/0x230 net/socket.c:1189
 sock_ioctl+0x1f8/0x680 net/socket.c:1306
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fb666e8c389
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:00007fb667bd3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb666fabf80 RCX: 00007fb666e8c389
RDX: 0000000000000000 RSI: 00000000000089e1 RDI: 0000000000000003
RBP: 00007fb666ed7493 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdc241fa0f R14: 00007fb667bd3300 R15: 0000000000022000
 </TASK>

The buggy address belongs to stack of task syz-executor.0/26984
 and is located at offset 40 in frame:
 sk_ioctl+0x0/0x440 net/core/sock.c:4172

This frame has 2 objects:
 [32, 36) 'karg'
 [48, 88) 'buffer'

The buggy address belongs to the virtual mapping at
 [ffffc900050c8000, ffffc900050d1000) created by:
 kernel_clone+0xeb/0x890 kernel/fork.c:2915

The buggy address belongs to the physical page:
page:ffffea00007ee580 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1fb96
memcg:ffff888020fc7402
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff888020fc7402
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 26967, tgid 26967 (syz-executor.0), ts 2188445839424, free_ts 2187756407399
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2db/0x350 mm/page_alloc.c:1731
 prep_new_page mm/page_alloc.c:1738 [inline]
 get_page_from_freelist+0xf41/0x2c00 mm/page_alloc.c:3502
 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4768
 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279
 vm_area_alloc_pages mm/vmalloc.c:3009 [inline]
 __vmalloc_area_node mm/vmalloc.c:3085 [inline]
 __vmalloc_node_range+0xb1c/0x14a0 mm/vmalloc.c:3257
 alloc_thread_stack_node kernel/fork.c:313 [inline]
 dup_task_struct kernel/fork.c:1116 [inline]
 copy_process+0x13bb/0x75c0 kernel/fork.c:2333
 kernel_clone+0xeb/0x890 kernel/fork.c:2915
 __do_sys_clone+0xba/0x100 kernel/fork.c:3058
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 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:1302 [inline]
 free_unref_page_prepare+0x62e/0xcb0 mm/page_alloc.c:2564
 free_unref_page_list+0xe3/0xa70 mm/page_alloc.c:2705
 release_pages+0xcd8/0x1380 mm/swap.c:1042
 tlb_batch_pages_flush+0xa8/0x1a0 mm/mmu_gather.c:97
 tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
 tlb_flush_mmu mm/mmu_gather.c:299 [inline]
 tlb_finish_mmu+0x14b/0x7e0 mm/mmu_gather.c:391
 exit_mmap+0x2b2/0x930 mm/mmap.c:3123
 __mmput+0x128/0x4c0 kernel/fork.c:1351
 mmput+0x60/0x70 kernel/fork.c:1373
 exit_mm kernel/exit.c:567 [inline]
 do_exit+0x9b0/0x29b0 kernel/exit.c:861
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1024
 get_signal+0x2318/0x25b0 kernel/signal.c:2876
 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
 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:286 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffffc900050cfa00: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00
 ffffc900050cfa80: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900050cfb00: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 04 f2 00 00
                                                          ^
 ffffc900050cfb80: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
 ffffc900050cfc00: 00 00 00 f1 f1 f1 f1 f1 f1 00 00 00 00 00 00 00
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