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BUG: KASAN: stack-out-of-bounds in ipmr_ioctl+0xb12/0xbd0 net/ipv4/ipmr.c:1654
Read of size 4 at addr ffffc9000e96fae4 by task syz-executor.2/3546

CPU: 0 PID: 3546 Comm: syz-executor.2 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
 ipmr_ioctl+0xb12/0xbd0 net/ipv4/ipmr.c:1654
 raw_ioctl+0x4e/0x1e0 net/ipv4/raw.c:881
 sock_ioctl_out net/core/sock.c:4186 [inline]
 sk_ioctl+0x151/0x440 net/core/sock.c:4214
 inet_ioctl+0x18c/0x380 net/ipv4/af_inet.c:1001
 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: 0033:0x7ff42b88c389
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:00007ff42c6bd168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff42b9abf80 RCX: 00007ff42b88c389
RDX: 0000000000000000 RSI: 00000000000089e1 RDI: 0000000000000003
RBP: 00007ff42b8d7493 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd6892aeaf R14: 00007ff42c6bd300 R15: 0000000000022000
 </TASK>

The buggy address belongs to stack of task syz-executor.2/3546
 and is located at offset 36 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
 [ffffc9000e968000, ffffc9000e971000) created by:
 kernel_clone+0xeb/0x890 kernel/fork.c:2915

The buggy address belongs to the physical page:
page:ffffea0000b30180 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2cc06
memcg:ffff88802352a082
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff88802352a082
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 3541, tgid 3541 (syz-executor.2), ts 1416481960784, free_ts 1324246094707
 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
 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:186 [inline]
 slab_post_alloc_hook mm/slab.h:711 [inline]
 slab_alloc_node mm/slub.c:3451 [inline]
 kmem_cache_alloc_node+0x185/0x3e0 mm/slub.c:3496
 __alloc_skb+0x288/0x330 net/core/skbuff.c:634
 alloc_skb include/linux/skbuff.h:1289 [inline]
 nlmsg_new include/net/netlink.h:1003 [inline]
 inet_netconf_notify_devconf+0xe1/0x260 net/ipv4/devinet.c:2105
 __devinet_sysctl_unregister net/ipv4/devinet.c:2617 [inline]
 devinet_sysctl_unregister net/ipv4/devinet.c:2641 [inline]
 inetdev_destroy net/ipv4/devinet.c:328 [inline]
 inetdev_event+0x10c3/0x1720 net/ipv4/devinet.c:1606
 notifier_call_chain+0xb6/0x3c0 kernel/notifier.c:93
 call_netdevice_notifiers_info+0xb9/0x130 net/core/dev.c:1962
 call_netdevice_notifiers_extack net/core/dev.c:2000 [inline]
 call_netdevice_notifiers net/core/dev.c:2014 [inline]
 unregister_netdevice_many_notify+0x75f/0x18c0 net/core/dev.c:10850
 vti6_exit_batch_net+0x3c3/0x730 net/ipv6/ip6_vti.c:1188
 ops_exit_list+0x125/0x170 net/core/net_namespace.c:175
 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:614
 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405

Memory state around the buggy address:
 ffffc9000e96f980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1
 ffffc9000e96fa00: f1 f1 f1 00 f3 f3 f3 00 00 00 00 00 00 00 00 00
>ffffc9000e96fa80: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 04 f2 00 00
                                                       ^
 ffffc9000e96fb00: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
 ffffc9000e96fb80: 00 00 00 f1 f1 f1 f1 f1 f1 00 00 00 00 00 f2 f2
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