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BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x677/0xcf0
Write of size 8 at addr ffff88802adf0658 by task syz.1.1198/10147

CPU: 0 UID: 0 PID: 10147 Comm: syz.1.1198 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 __bpf_get_stackid+0x677/0xcf0
 bpf_get_stackid_raw_tp+0x196/0x210
 bpf_prog_12712c88fd19bd5b+0x2a/0x32
 bpf_trace_run4+0x28e/0x4a0
 trace_mm_page_alloc+0x129/0x150
 __alloc_frozen_pages_noprof+0x1d6/0x370
 __alloc_pages_noprof+0xa/0x30
 bpf_ringbuf_alloc+0x254/0x590
 ringbuf_map_alloc+0x1c8/0x2f0
 map_create+0xaa3/0x14d0
 __sys_bpf+0x60f/0x870
 __x64_sys_bpf+0x7c/0x90
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8711f8ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8712e10038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f87121c5fa0 RCX: 00007f8711f8ebe9
RDX: 0000000000000048 RSI: 00002000000007c0 RDI: 0000000000000000
RBP: 00007f8712011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f87121c6038 R14: 00007f87121c5fa0 R15: 00007ffc1084ab58
 </TASK>

Allocated by task 10147:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_node_noprof+0x276/0x4e0
 bpf_map_area_alloc+0x64/0x180
 prealloc_elems_and_freelist+0x86/0x1d0
 stack_map_alloc+0x33f/0x4c0
 map_create+0xaa3/0x14d0
 __sys_bpf+0x60f/0x870
 __x64_sys_bpf+0x7c/0x90
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802adf0000
 which belongs to the cache kmalloc-cg-2k of size 2048
The buggy address is located 24 bytes to the right of
 allocated 1600-byte region [ffff88802adf0000, ffff88802adf0640)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2adf0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88803cc8e501
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801a44b3c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000080008 00000000f5000000 ffff88803cc8e501
head: 00fff00000000040 ffff88801a44b3c0 dead000000000100 dead000000000122
head: 0000000000000000 0000000000080008 00000000f5000000 ffff88803cc8e501
head: 00fff00000000003 ffffea0000ab7c01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5851, tgid 5851 (syz-executor), ts 54558951049, free_ts 54557320697
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x8a/0x370
 ___slab_alloc+0xbeb/0x1410
 __kmalloc_noprof+0x305/0x4f0
 __register_sysctl_table+0x72/0x1340
 __devinet_sysctl_register+0x37f/0x470
 devinet_sysctl_register+0x187/0x200
 inetdev_init+0x2b4/0x500
 inetdev_event+0x301/0x15b0
 notifier_call_chain+0x1b6/0x3e0
 register_netdevice+0x1608/0x1ae0
 register_netdev+0x40/0x60
 loopback_net_init+0x75/0x150
page last free pid 5851 tgid 5851 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __slab_free+0x303/0x3c0
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 __kmalloc_cache_noprof+0x1be/0x3d0
 ref_tracker_alloc+0x133/0x460
 register_netdevice+0x14a3/0x1ae0
 register_netdev+0x40/0x60
 loopback_net_init+0x75/0x150
 ops_init+0x35c/0x5c0
 setup_net+0x10c/0x320
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0

Memory state around the buggy address:
 ffff88802adf0500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88802adf0580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88802adf0600: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                                    ^
 ffff88802adf0680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802adf0700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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