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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 ffffc900051bfb68 by task syz-executor.4/19557

CPU: 0 PID: 19557 Comm: syz-executor.4 Not tainted 6.4.0-rc6-syzkaller-01333-g9a94d764e9bc #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: 0033:0x7fada148c389
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:00007fada21ac168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fada15abf80 RCX: 00007fada148c389
RDX: 0000000000000000 RSI: 00000000000089e1 RDI: 0000000000000003
RBP: 00007fada14d7493 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff0986bf9f R14: 00007fada21ac300 R15: 0000000000022000
 </TASK>

The buggy address belongs to stack of task syz-executor.4/19557
 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
 [ffffc900051b8000, ffffc900051c1000) created by:
 kernel_clone+0xeb/0x890 kernel/fork.c:2915

The buggy address belongs to the physical page:
page:ffffea0000ec3280 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3b0ca
memcg:ffff8880277a6002
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff8880277a6002
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 12427, tgid 12427 (syz-executor.2), ts 1820125515333, free_ts 1816469688609
 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+0x33/0x370 mm/page_alloc.c:2659
 kasan_depopulate_vmalloc_pte+0x60/0x80 mm/kasan/shadow.c:427
 apply_to_pte_range mm/memory.c:2585 [inline]
 apply_to_pmd_range mm/memory.c:2629 [inline]
 apply_to_pud_range mm/memory.c:2665 [inline]
 apply_to_p4d_range mm/memory.c:2701 [inline]
 __apply_to_page_range+0x68c/0x1030 mm/memory.c:2735
 kasan_release_vmalloc+0xab/0xc0 mm/kasan/shadow.c:544
 __purge_vmap_area_lazy+0x886/0x1e60 mm/vmalloc.c:1771
 drain_vmap_area_work+0x54/0xd0 mm/vmalloc.c:1804
 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405
 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552
 kthread+0x344/0x440 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Memory state around the buggy address:
 ffffc900051bfa00: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00
 ffffc900051bfa80: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900051bfb00: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 04 f2 00 00
                                                          ^
 ffffc900051bfb80: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
 ffffc900051bfc00: 00 00 00 f1 f1 f1 f1 f1 f1 00 00 00 00 00 00 00
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