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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 ffffc90015317b68 by task syz-executor.3/5777

CPU: 1 PID: 5777 Comm: syz-executor.3 Not tainted 6.4.0-rc7-next-20230621-syzkaller #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:364
 print_report mm/kasan/report.c:475 [inline]
 kasan_report+0x11d/0x130 mm/kasan/report.c:588
 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:1190
 sock_ioctl+0x1f8/0x680 net/socket.c:1307
 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+0x19d/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: 0033:0x7f4c23c8c389
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:00007f4c249cc168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4c23dabf80 RCX: 00007f4c23c8c389
RDX: 0000000000000000 RSI: 00000000000089e1 RDI: 0000000000000003
RBP: 00007f4c23cd7493 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcb560d6bf R14: 00007f4c249cc300 R15: 0000000000022000
 </TASK>

The buggy address belongs to stack of task syz-executor.3/5777
 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
 [ffffc90015310000, ffffc90015319000) created by:
 kernel_clone+0xeb/0x890 kernel/fork.c:2911

The buggy address belongs to the physical page:
page:ffffea00008d6980 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x235a6
memcg:ffff888078b57002
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff888078b57002
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 5722, tgid 5722 (syz-executor.5), ts 337804992217, free_ts 321817057168
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2db/0x350 mm/page_alloc.c:1570
 prep_new_page mm/page_alloc.c:1577 [inline]
 get_page_from_freelist+0xfc2/0x2b00 mm/page_alloc.c:3257
 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4513
 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279
 vm_area_alloc_pages mm/vmalloc.c:3059 [inline]
 __vmalloc_area_node mm/vmalloc.c:3135 [inline]
 __vmalloc_node_range+0xb73/0x14b0 mm/vmalloc.c:3316
 alloc_thread_stack_node kernel/fork.c:309 [inline]
 dup_task_struct kernel/fork.c:1112 [inline]
 copy_process+0x13bb/0x75c0 kernel/fork.c:2329
 kernel_clone+0xeb/0x890 kernel/fork.c:2911
 __do_sys_clone+0xba/0x100 kernel/fork.c:3054
 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:1161 [inline]
 free_unref_page_prepare+0x4dd/0xb90 mm/page_alloc.c:2384
 free_unref_page+0x33/0x370 mm/page_alloc.c:2479
 __unfreeze_partials+0x1fe/0x220 mm/slub.c:2647
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x195/0x220 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x63/0x90 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook mm/slab.h:750 [inline]
 slab_alloc_node mm/slub.c:3470 [inline]
 kmem_cache_alloc_node+0x1c6/0x3e0 mm/slub.c:3515
 __alloc_skb+0x288/0x330 net/core/skbuff.c:634
 alloc_skb include/linux/skbuff.h:1289 [inline]
 alloc_skb_with_frags+0x9a/0x6f0 net/core/skbuff.c:6222
 sock_alloc_send_pskb+0x7a7/0x930 net/core/sock.c:2777
 sock_alloc_send_skb include/net/sock.h:1873 [inline]
 mld_newpack.isra.0+0x1b9/0x760 net/ipv6/mcast.c:1748
 add_grhead+0x295/0x340 net/ipv6/mcast.c:1851
 add_grec+0x1053/0x1610 net/ipv6/mcast.c:1989
 mld_send_cr net/ipv6/mcast.c:2115 [inline]
 mld_ifc_work+0x42c/0xe20 net/ipv6/mcast.c:2653
 process_one_work+0xa34/0x16f0 kernel/workqueue.c:2594
 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2745

Memory state around the buggy address:
 ffffc90015317a00: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00
 ffffc90015317a80: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90015317b00: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 04 f2 00 00
                                                          ^
 ffffc90015317b80: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
 ffffc90015317c00: 00 00 00 f1 f1 f1 f1 f1 f1 00 00 00 00 00 00 00
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