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BUG: KASAN: slab-out-of-bounds in __xfrm_state_lookup+0x6ad/0x8d0
Read of size 2 at addr ffff888118041342 by task syz.2.3007/12826

CPU: 0 UID: 0 PID: 12826 Comm: syz.2.3007 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
 __xfrm_state_lookup+0x6ad/0x8d0
 xfrm_state_lookup+0x11e/0x1e0
 ipcomp4_init_state+0x205/0xb20
 __xfrm_init_state+0xa76/0x13f0
 xfrm_add_sa+0x2f5b/0x4070
 xfrm_user_rcv_msg+0x7a3/0xab0
 netlink_rcv_skb+0x208/0x470
 xfrm_netlink_rcv+0x79/0x90
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc3d438ebe9
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:00007fc3d51ed038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc3d45c5fa0 RCX: 00007fc3d438ebe9
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000003
RBP: 00007fc3d4411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc3d45c6038 R14: 00007fc3d45c5fa0 R15: 00007ffc883115c8
 </TASK>

Allocated by task 12547:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 alloc_netdev_mqs+0xb90/0x11b0
 sit_init_net+0x151/0x5c0
 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
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 10782:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 free_netdev+0x128/0x700
 netdev_run_todo+0xd0c/0xea0
 ops_undo_list+0x3e1/0x990
 cleanup_net+0x4c5/0x800
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff888118041200
 which belongs to the cache kmalloc-cg-256 of size 256
The buggy address is located 66 bytes to the right of
 allocated 256-byte region [ffff888118041200, ffff888118041300)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888118041e00 pfn:0x118040
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8881188a2801
anon flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801a44b000 0000000000000000 0000000000000001
raw: ffff888118041e00 0000000000100002 00000000f5000000 ffff8881188a2801
head: 057ff00000000040 ffff88801a44b000 0000000000000000 0000000000000001
head: ffff888118041e00 0000000000100002 00000000f5000000 ffff8881188a2801
head: 057ff00000000001 ffffea0004601001 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 12009, tgid 12008 (syz.2.2645), ts 175558418511, free_ts 174421654224
 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_node_track_caller_noprof+0x2f8/0x4e0
 krealloc_noprof+0x124/0x340
 copy_array+0x63/0xf0
 copy_verifier_state+0x958/0xf10
 do_check+0x4017/0xe520
 do_check_common+0x1949/0x24f0
 bpf_check+0x1746a/0x1d2d0
 bpf_prog_load+0x1318/0x1930
 __sys_bpf+0x528/0x870
 __x64_sys_bpf+0x7c/0x90
page last free pid 5832 tgid 5832 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __put_partials+0x156/0x1a0
 put_cpu_partial+0x17c/0x250
 __slab_free+0x2d5/0x3c0
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_node_noprof+0x1bb/0x3c0
 __alloc_skb+0x112/0x2d0
 tcp_stream_alloc_skb+0x3d/0x340
 tcp_sendmsg_locked+0xf38/0x5620
 tcp_sendmsg+0x2f/0x50
 __sock_sendmsg+0x19c/0x270
 sock_write_iter+0x258/0x330
 vfs_write+0x5c9/0xb30
 ksys_write+0x145/0x250

Memory state around the buggy address:
 ffff888118041200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888118041280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888118041300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                           ^
 ffff888118041380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888118041400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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