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BUG: KASAN: slab-out-of-bounds in xfrm_alloc_spi+0x570/0xf30
Read of size 4 at addr ffff88811c9dce44 by task syz.1.9950/28666

CPU: 1 UID: 0 PID: 28666 Comm: syz.1.9950 Not tainted 6.16.0-syzkaller-06588-g759dfc7d04ba #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_alloc_spi+0x570/0xf30
 xfrm_alloc_userspi+0x70b/0xc90
 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: 0033:0x7f6fd658eb69
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:00007f6fd74d9038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f6fd67b5fa0 RCX: 00007f6fd658eb69
RDX: 0000000000000000 RSI: 0000200000000540 RDI: 0000000000000003
RBP: 00007f6fd6611df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6fd67b5fa0 R15: 00007ffe5db2bf08
 </TASK>

Allocated by task 1012:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x27a/0x4f0
 fib6_info_alloc+0x30/0xf0
 ip6_route_info_create+0x142/0x860
 ip6_route_add+0x49/0x1b0
 addrconf_add_dev+0x24f/0x340
 addrconf_init_auto_addrs+0x57c/0xa30
 addrconf_notify+0xacc/0x1010
 notifier_call_chain+0x1b6/0x3e0
 netif_state_change+0x284/0x3a0
 linkwatch_do_dev+0x117/0x170
 __linkwatch_run_queue+0x56a/0x7e0
 linkwatch_event+0x4c/0x60
 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 ffff88811c9dcc00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 276 bytes to the right of
 allocated 304-byte region [ffff88811c9dcc00, ffff88811c9dcd30)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11c9dc
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801a441c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801a441c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea0004727701 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 26069, tgid 26069 (syz-executor), ts 305728439412, free_ts 288410567787
 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/0x3b0
 ___slab_alloc+0xbfc/0x1480
 __kmalloc_noprof+0x305/0x4f0
 fib6_info_alloc+0x30/0xf0
 ip6_route_info_create+0x142/0x860
 ip6_route_add+0x49/0x1b0
 inet6_addr_add+0x6b2/0xc00
 inet6_rtm_newaddr+0x93d/0xd20
 rtnetlink_rcv_msg+0x7cf/0xb70
 netlink_rcv_skb+0x208/0x470
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
page last free pid 24811 tgid 24811 stack trace:
 __free_frozen_pages+0xc71/0xe70
 __slab_free+0x326/0x400
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 security_inode_alloc+0x39/0x330
 inode_init_always_gfp+0x9ed/0xdc0
 alloc_inode+0x82/0x1b0
 new_inode+0x22/0x170
 proc_pid_make_inode+0x21/0x130
 proc_pid_instantiate+0x53/0x2b0
 proc_pid_lookup+0x2fa/0x420
 proc_root_lookup+0x20/0x50
 __lookup_slow+0x297/0x3d0
 lookup_slow+0x53/0x70

Memory state around the buggy address:
 ffff88811c9dcd00: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
 ffff88811c9dcd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88811c9dce00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                           ^
 ffff88811c9dce80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88811c9dcf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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