================================================================== BUG: KASAN: use-after-free in decode_session6+0xfc3/0x17f0 net/xfrm/xfrm_policy.c:3376 Read of size 1 at addr ffff88806eba5442 by task swapper/0/0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.0.0-rc2-syzkaller-00283-g10d4879f9ef0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 decode_session6+0xfc3/0x17f0 net/xfrm/xfrm_policy.c:3376 __xfrm_decode_session+0x50/0xb0 net/xfrm/xfrm_policy.c:3482 xfrm_decode_session include/net/xfrm.h:1160 [inline] vti6_tnl_xmit+0x419/0x1f90 net/ipv6/ip6_vti.c:577 __netdev_start_xmit include/linux/netdevice.h:4819 [inline] netdev_start_xmit include/linux/netdevice.h:4833 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x183/0x880 net/core/dev.c:3606 sch_direct_xmit+0x19f/0xbe0 net/sched/sch_generic.c:342 qdisc_restart net/sched/sch_generic.c:407 [inline] __qdisc_run+0x4bb/0x1710 net/sched/sch_generic.c:415 __dev_xmit_skb net/core/dev.c:3880 [inline] __dev_queue_xmit+0x2299/0x3ad0 net/core/dev.c:4222 dev_queue_xmit include/linux/netdevice.h:3008 [inline] neigh_connected_output+0x3c0/0x520 net/core/neighbour.c:1581 neigh_output include/net/neighbour.h:551 [inline] ip6_finish_output2+0x564/0x1520 net/ipv6/ip6_output.c:134 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline] ip6_finish_output+0x690/0x1160 net/ipv6/ip6_output.c:206 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1ed/0x540 net/ipv6/ip6_output.c:227 dst_output include/net/dst.h:451 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0xa5f/0x1730 net/ipv6/ndisc.c:508 ndisc_send_rs+0x12e/0x6f0 net/ipv6/ndisc.c:718 addrconf_rs_timer+0x3ed/0x820 net/ipv6/addrconf.c:3927 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline] RIP: 0010:acpi_safe_halt+0x6f/0xb0 drivers/acpi/processor_idle.c:113 Code: f7 84 db 74 06 5b e9 f0 8f f9 f7 e8 eb 8f f9 f7 e8 16 07 00 f8 66 90 e8 df 8f f9 f7 0f 00 2d a8 43 d2 00 e8 d3 8f f9 f7 fb f4 <9c> 5b 81 e3 00 02 00 00 fa 31 ff 48 89 de e8 9e 8c f9 f7 48 85 db RSP: 0018:ffffffff8bc07d38 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffffffff8bcbc980 RSI: ffffffff89827b3d RDI: 0000000000000000 RBP: ffff888145a99064 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000001 R14: ffff888145a99000 R15: ffff888146652004 acpi_idle_do_entry drivers/acpi/processor_idle.c:555 [inline] acpi_idle_enter+0x524/0x6a0 drivers/acpi/processor_idle.c:692 cpuidle_enter_state+0x1ab/0xd30 drivers/cpuidle/cpuidle.c:239 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:356 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:236 [inline] do_idle+0x3e8/0x590 kernel/sched/idle.c:303 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:400 rest_init+0x169/0x270 init/main.c:727 arch_call_rest_init+0xf/0x14 init/main.c:883 start_kernel+0x46e/0x48f init/main.c:1138 secondary_startup_64_no_verify+0xce/0xdb Allocated by task 8179: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:437 [inline] ____kasan_kmalloc mm/kasan/common.c:516 [inline] ____kasan_kmalloc mm/kasan/common.c:475 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525 kmalloc include/linux/slab.h:605 [inline] io_alloc_async_data+0xa5/0x160 io_uring/io_uring.c:1434 io_recvmsg_alloc_async io_uring/net.c:145 [inline] io_setup_async_msg.part.0+0x1b7/0x410 io_uring/net.c:159 io_setup_async_msg io_uring/net.c:744 [inline] io_recvmsg+0x1627/0x1df0 io_uring/net.c:746 io_issue_sqe+0x6b6/0xd20 io_uring/io_uring.c:1577 io_queue_sqe io_uring/io_uring.c:1754 [inline] io_submit_sqe io_uring/io_uring.c:2012 [inline] io_submit_sqes+0x94e/0x1d30 io_uring/io_uring.c:2123 __do_sys_io_uring_enter+0xb85/0x1ea0 io_uring/io_uring.c:3054 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 2406: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:367 [inline] ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1754 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780 slab_free mm/slub.c:3534 [inline] kfree+0xe2/0x580 mm/slub.c:4562 io_alloc_cache_free+0xf6/0x13a io_uring/alloc_cache.h:49 io_ring_ctx_free io_uring/io_uring.c:2440 [inline] io_ring_exit_work+0x6c6/0xc4c io_uring/io_uring.c:2627 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 call_rcu+0x99/0x790 kernel/rcu/tree.c:2793 fib6_info_release include/net/ip6_fib.h:340 [inline] fib6_info_release include/net/ip6_fib.h:337 [inline] fixup_permanent_addr net/ipv6/addrconf.c:3472 [inline] addrconf_permanent_addr net/ipv6/addrconf.c:3500 [inline] addrconf_notify+0x1651/0x1b90 net/ipv6/addrconf.c:3568 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1945 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline] call_netdevice_notifiers net/core/dev.c:1997 [inline] __dev_notify_flags+0x110/0x2b0 net/core/dev.c:8594 dev_change_flags+0x112/0x170 net/core/dev.c:8632 do_setlink+0x961/0x3bb0 net/core/rtnetlink.c:2780 __rtnl_newlink+0xd6a/0x17e0 net/core/rtnetlink.c:3546 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3593 rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6090 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 __sys_sendto+0x236/0x340 net/socket.c:2117 __do_sys_sendto net/socket.c:2129 [inline] __se_sys_sendto net/socket.c:2125 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2125 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88806eba5400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 66 bytes inside of 512-byte region [ffff88806eba5400, ffff88806eba5600) The buggy address belongs to the physical page: page:ffffea0001bae900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6eba4 head:ffffea0001bae900 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888011841c80 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3599, tgid 3598 (syz-fuzzer), ts 57339119540, free_ts 12394410309 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1824 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1969 new_slab mm/slub.c:2029 [inline] ___slab_alloc+0x7f1/0xe10 mm/slub.c:3031 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118 slab_alloc_node mm/slub.c:3209 [inline] __kmalloc_node_track_caller+0x2f2/0x380 mm/slub.c:4955 kmalloc_reserve net/core/skbuff.c:358 [inline] __alloc_skb+0xd9/0x2f0 net/core/skbuff.c:430 __napi_alloc_skb+0x93/0x340 net/core/skbuff.c:571 napi_alloc_skb include/linux/skbuff.h:3186 [inline] page_to_skb+0x17d/0xc10 drivers/net/virtio_net.c:496 receive_mergeable drivers/net/virtio_net.c:1119 [inline] receive_buf+0xe0a/0x5560 drivers/net/virtio_net.c:1258 virtnet_receive drivers/net/virtio_net.c:1553 [inline] virtnet_poll+0x708/0x1310 drivers/net/virtio_net.c:1671 __napi_poll+0xb3/0x6d0 net/core/dev.c:6511 napi_poll net/core/dev.c:6578 [inline] net_rx_action+0x9c1/0xd90 net/core/dev.c:6689 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1449 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476 free_contig_range+0xb1/0x180 mm/page_alloc.c:9408 destroy_args+0xa8/0x646 mm/debug_vm_pgtable.c:1031 debug_vm_pgtable+0x2945/0x29d6 mm/debug_vm_pgtable.c:1354 do_one_initcall+0xfe/0x650 init/main.c:1296 do_initcall_level init/main.c:1369 [inline] do_initcalls init/main.c:1385 [inline] do_basic_setup init/main.c:1404 [inline] kernel_init_freeable+0x6b1/0x73a init/main.c:1623 kernel_init+0x1a/0x1d0 init/main.c:1512 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Memory state around the buggy address: ffff88806eba5300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88806eba5380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88806eba5400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806eba5480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806eba5500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: f7 84 db 74 06 5b e9 testl $0xf7f98ff0,-0x16a4f98c(%rbx,%rbx,8) 7: f0 8f f9 f7 b: e8 eb 8f f9 f7 callq 0xf7f98ffb 10: e8 16 07 00 f8 callq 0xf800072b 15: 66 90 xchg %ax,%ax 17: e8 df 8f f9 f7 callq 0xf7f98ffb 1c: 0f 00 2d a8 43 d2 00 verw 0xd243a8(%rip) # 0xd243cb 23: e8 d3 8f f9 f7 callq 0xf7f98ffb 28: fb sti 29: f4 hlt * 2a: 9c pushfq <-- trapping instruction 2b: 5b pop %rbx 2c: 81 e3 00 02 00 00 and $0x200,%ebx 32: fa cli 33: 31 ff xor %edi,%edi 35: 48 89 de mov %rbx,%rsi 38: e8 9e 8c f9 f7 callq 0xf7f98cdb 3d: 48 85 db test %rbx,%rbx