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BUG: KASAN: use-after-free in decode_session6 net/xfrm/xfrm_policy.c:3390 [inline]
BUG: KASAN: use-after-free in __xfrm_decode_session+0x1af8/0x26c0 net/xfrm/xfrm_policy.c:3482
Read of size 1 at addr ffff88809bf6114b by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc2+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113
 print_address_description+0x75/0x5c0 mm/kasan/report.c:374
 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:506
 kasan_report+0x26/0x50 mm/kasan/common.c:634
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/generic_report.c:129
 decode_session6 net/xfrm/xfrm_policy.c:3390 [inline]
 __xfrm_decode_session+0x1af8/0x26c0 net/xfrm/xfrm_policy.c:3482
 vti6_tnl_xmit+0x3ee/0x1710 net/ipv6/ip6_vti.c:531
 __netdev_start_xmit include/linux/netdevice.h:4420 [inline]
 netdev_start_xmit include/linux/netdevice.h:4434 [inline]
 xmit_one net/core/dev.c:3280 [inline]
 dev_hard_start_xmit+0x1c1/0x3f0 net/core/dev.c:3296
 sch_direct_xmit+0x1e8/0xd60 net/sched/sch_generic.c:313
 qdisc_restart net/sched/sch_generic.c:376 [inline]
 __qdisc_run+0xa2b/0x1b60 net/sched/sch_generic.c:384
 __dev_xmit_skb net/core/dev.c:3537 [inline]
 __dev_queue_xmit+0x1248/0x3010 net/core/dev.c:3842
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3906
 neigh_direct_output+0x15/0x20 net/core/neighbour.c:1530
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x102c/0x13b0 net/ipv6/ip6_output.c:116
 __ip6_finish_output+0x693/0x8c0 net/ipv6/ip6_output.c:142
 ip6_finish_output+0x52/0x1e0 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x26f/0x370 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ndisc_send_skb+0xa35/0xe20 net/ipv6/ndisc.c:505
 ndisc_send_rs+0x4ec/0x680 net/ipv6/ndisc.c:699
 addrconf_rs_timer+0x22e/0x5f0 net/ipv6/addrconf.c:3879
 call_timer_fn+0x95/0x170 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers+0x7b6/0x990 kernel/time/timer.c:1773
 run_timer_softirq+0x4a/0x90 kernel/time/timer.c:1786
 __do_softirq+0x333/0x7c4 arch/x86/include/asm/paravirt.h:766
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x227/0x230 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x113/0x280 arch/x86/kernel/apic/apic.c:1137
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 </IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: 3a fa eb ae 89 d9 80 e1 07 80 c1 03 38 c1 7c ba 48 89 df e8 b4 c5 3a fa eb b0 90 90 e9 07 00 00 00 0f 00 2d b6 f9 50 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d a6 f9 50 00 f4 c3 90 90 55 48 89 e5
RSP: 0018:ffffffff88807dc0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff1115231 RBX: ffffffff88875a00 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffffff812b7b5a RDI: ffffffff88876244
RBP: ffffffff88807dc8 R08: ffffffff88876258 R09: fffffbfff110eb41
R10: fffffbfff110eb41 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffffffff110eb40 R14: dffffc0000000000 R15: 1ffffffff111522f
 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571
 default_idle_call+0x59/0xa0 kernel/sched/idle.c:94
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x140/0x670 kernel/sched/idle.c:263
 cpu_startup_entry+0x25/0x30 kernel/sched/idle.c:355
 rest_init+0x29d/0x2b0 init/main.c:451
 arch_call_rest_init+0xe/0x10
 start_kernel+0x6d1/0x7d2 init/main.c:784
 x86_64_start_reservations+0x18/0x2e arch/x86/kernel/head64.c:472
 x86_64_start_kernel+0x7a/0x7d arch/x86/kernel/head64.c:453
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241

Allocated by task 15261:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:510
 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:518
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slab.c:3262 [inline]
 kmem_cache_alloc_node+0x235/0x280 mm/slab.c:3574
 __alloc_skb+0x9f/0x500 net/core/skbuff.c:197
 alloc_skb include/linux/skbuff.h:1049 [inline]
 alloc_skb_with_frags+0xb6/0x600 net/core/skbuff.c:5659
 sock_alloc_send_pskb+0x7cc/0xbc0 net/core/sock.c:2240
 unix_dgram_sendmsg+0x612/0x2460 net/unix/af_unix.c:1625
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg net/socket.c:657 [inline]
 ___sys_sendmsg+0x60d/0x910 net/socket.c:2311
 __sys_sendmmsg+0x239/0x470 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2439
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 15262:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 kasan_set_free_info mm/kasan/common.c:332 [inline]
 __kasan_slab_free+0x12a/0x1e0 mm/kasan/common.c:471
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480
 __cache_free mm/slab.c:3425 [inline]
 kmem_cache_free+0x81/0xf0 mm/slab.c:3693
 kfree_skbmem net/core/skbuff.c:644 [inline]
 __kfree_skb+0x118/0x170 net/core/skbuff.c:680
 consume_skb+0x6b/0xb0 net/core/skbuff.c:838
 skb_free_datagram+0x28/0xd0 net/core/datagram.c:328
 unix_dgram_recvmsg+0xa67/0xeb0 net/unix/af_unix.c:2127
 sock_recvmsg_nosec+0x8a/0xa0 net/socket.c:871
 ___sys_recvmsg+0x5af/0x910 net/socket.c:2480
 do_recvmmsg+0x2ca/0x7c0 net/socket.c:2601
 __sys_recvmmsg net/socket.c:2680 [inline]
 __do_sys_recvmmsg net/socket.c:2703 [inline]
 __se_sys_recvmmsg net/socket.c:2696 [inline]
 __x64_sys_recvmmsg+0x130/0x1c0 net/socket.c:2696
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88809bf61080
 which belongs to the cache skbuff_head_cache(65:syz3) of size 224
The buggy address is located 203 bytes inside of
 224-byte region [ffff88809bf61080, ffff88809bf61160)
The buggy address belongs to the page:
page:ffffea00026fd840 refcount:1 mapcount:0 mapping:ffff8880939ad540 index:0x0
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea00029ee3c8 ffffea0002924f88 ffff8880939ad540
raw: 0000000000000000 ffff88809bf61080 000000010000000c 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809bf61000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809bf61080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88809bf61100: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                                              ^
 ffff88809bf61180: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff88809bf61200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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