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BUG: KASAN: slab-out-of-bounds in __xfrm_state_lookup+0x6ad/0x8d0
Read of size 2 at addr ffff88802e7c0a42 by task syz.1.1157/10165

CPU: 0 UID: 0 PID: 10165 Comm: syz.1.1157 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_update+0x20a/0x1270
 xfrm_add_sa+0x35b2/0x4070
 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: 0033:0x7f8c50b8ec29
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:00007f8c519ea038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8c50dd5fa0 RCX: 00007f8c50b8ec29
RDX: 0000000000002000 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f8c50c11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8c50dd6038 R14: 00007f8c50dd5fa0 R15: 00007ffd2c1e34f8
 </TASK>

Allocated by task 10154:
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 skb_clone+0x212/0x3a0
 __netlink_deliver_tap+0x404/0x850
 netlink_deliver_tap+0x19c/0x1b0
 netlink_unicast+0x7fa/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

Freed by task 10154:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kmem_cache_free+0x18f/0x400
 nlmon_xmit+0xb0/0x100
 dev_hard_start_xmit+0x2d7/0x830
 __dev_queue_xmit+0x1b8d/0x3b50
 __netlink_deliver_tap+0x5ad/0x850
 netlink_deliver_tap+0x19c/0x1b0
 netlink_unicast+0x7fa/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

The buggy address belongs to the object at ffff88802e7c0900
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 82 bytes to the right of
 allocated 240-byte region [ffff88802e7c0900, ffff88802e7c09f0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2e7c0
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888100ab8a00 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000150015 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff888100ab8a00 0000000000000000 dead000000000001
head: 0000000000000000 0000000000150015 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffea0000b9f001 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 9363, tgid 9361 (syz.2.956), ts 169859715297, free_ts 167869130242
 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/0x1420
 kmem_cache_alloc_noprof+0x283/0x3c0
 skb_clone+0x212/0x3a0
 ip_mc_output+0x1eb/0x590
 ip_send_skb+0x74/0x100
 udp_send_skb+0xaf1/0x14c0
 udp_sendmsg+0x195a/0x2170
 __sock_sendmsg+0x19c/0x270
 ____sys_sendmsg+0x52d/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __sys_sendmmsg+0x227/0x430
page last free pid 793 tgid 793 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 kasan_depopulate_vmalloc_pte+0x6d/0x90
 __apply_to_page_range+0xb66/0x13d0
 kasan_release_vmalloc+0xa2/0xd0
 purge_vmap_node+0x214/0x8f0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30

Memory state around the buggy address:
 ffff88802e7c0900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802e7c0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
>ffff88802e7c0a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                           ^
 ffff88802e7c0a80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802e7c0b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
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