================================================================== BUG: KASAN: use-after-free in decode_session6+0xe6d/0x1530 net/xfrm/xfrm_policy.c:3369 Read of size 1 at addr ffff88801a0c0dbc by task syz-executor.2/22668 CPU: 1 PID: 22668 Comm: syz-executor.2 Not tainted 5.16.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247 __kasan_report mm/kasan/report.c:433 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:450 decode_session6+0xe6d/0x1530 net/xfrm/xfrm_policy.c:3369 __xfrm_decode_session+0x50/0xb0 net/xfrm/xfrm_policy.c:3456 xfrm_decode_session include/net/xfrm.h:1149 [inline] vti6_tnl_xmit+0x41f/0x1fe0 net/ipv6/ip6_vti.c:577 __netdev_start_xmit include/linux/netdevice.h:4608 [inline] netdev_start_xmit include/linux/netdevice.h:4622 [inline] xmit_one net/core/dev.c:3473 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3489 sch_direct_xmit+0x19f/0xbc0 net/sched/sch_generic.c:342 qdisc_restart net/sched/sch_generic.c:407 [inline] __qdisc_run+0x4bc/0x1700 net/sched/sch_generic.c:415 __dev_xmit_skb net/core/dev.c:3758 [inline] __dev_queue_xmit+0x2084/0x3620 net/core/dev.c:4077 neigh_connected_output+0x3b6/0x510 net/core/neighbour.c:1552 neigh_output include/net/neighbour.h:538 [inline] ip6_finish_output2+0x56e/0x14f0 net/ipv6/ip6_output.c:126 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline] __ip6_finish_output+0x61e/0xe80 net/ipv6/ip6_output.c:170 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:450 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0xa99/0x17f0 net/ipv6/ndisc.c:508 ndisc_send_rs+0x12e/0x6f0 net/ipv6/ndisc.c:702 addrconf_rs_timer+0x3f2/0x820 net/ipv6/addrconf.c:3898 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 Code: 74 24 10 e8 aa fd 14 f8 48 89 ef e8 f2 73 15 f8 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 b3 3d 08 f8 65 8b 05 9c c0 ba 76 85 c0 74 0a 5b 5d c3 e8 90 2d RSP: 0018:ffffc900045cf798 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff1b22679 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffffff906b36d8 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817ddd38 R11: 000000000000001f R12: 000000000000000e R13: 000000000000000e R14: dead000000000100 R15: dffffc0000000000 __debug_check_no_obj_freed lib/debugobjects.c:1002 [inline] debug_check_no_obj_freed+0x20c/0x420 lib/debugobjects.c:1023 free_pages_prepare mm/page_alloc.c:1343 [inline] free_pcp_prepare+0x2ae/0x870 mm/page_alloc.c:1389 free_unref_page_prepare mm/page_alloc.c:3309 [inline] free_unref_page_list+0x1a9/0xfa0 mm/page_alloc.c:3425 release_pages+0x3f4/0x1480 mm/swap.c:980 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:242 [inline] tlb_flush_mmu mm/mmu_gather.c:249 [inline] tlb_finish_mmu+0x165/0x8c0 mm/mmu_gather.c:340 exit_mmap+0x1ea/0x630 mm/mmap.c:3172 __mmput+0x122/0x4b0 kernel/fork.c:1113 mmput+0x56/0x60 kernel/fork.c:1134 exit_mm kernel/exit.c:507 [inline] do_exit+0xb27/0x2b40 kernel/exit.c:819 do_group_exit+0x125/0x310 kernel/exit.c:929 get_signal+0x47d/0x2220 kernel/signal.c:2852 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f8491722ae9 Code: Unable to access opcode bytes at RIP 0x7f8491722abf. RSP: 002b:00007f848ec98218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 00007f8491835f68 RCX: 00007f8491722ae9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8491835f68 RBP: 00007f8491835f60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8491835f6c R13: 00007ffccd822d4f R14: 00007f848ec98300 R15: 0000000000022000 Allocated by task 21286: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:595 [inline] tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x272/0x380 security/tomoyo/file.c:771 tomoyo_file_open security/tomoyo/tomoyo.c:311 [inline] tomoyo_file_open+0xa3/0xd0 security/tomoyo/tomoyo.c:306 security_file_open+0x45/0xb0 security/security.c:1635 do_dentry_open+0x353/0x1250 fs/open.c:809 do_open fs/namei.c:3426 [inline] path_openat+0x1cad/0x2750 fs/namei.c:3559 do_filp_open+0x1aa/0x400 fs/namei.c:3586 do_sys_openat2+0x16d/0x4d0 fs/open.c:1212 do_sys_open fs/open.c:1228 [inline] __do_sys_open fs/open.c:1236 [inline] __se_sys_open fs/open.c:1232 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1232 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+0x44/0xae Freed by task 21286: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749 slab_free mm/slub.c:3513 [inline] kfree+0xf6/0x560 mm/slub.c:4561 tomoyo_realpath_from_path+0x191/0x620 security/tomoyo/realpath.c:291 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x272/0x380 security/tomoyo/file.c:771 tomoyo_file_open security/tomoyo/tomoyo.c:311 [inline] tomoyo_file_open+0xa3/0xd0 security/tomoyo/tomoyo.c:306 security_file_open+0x45/0xb0 security/security.c:1635 do_dentry_open+0x353/0x1250 fs/open.c:809 do_open fs/namei.c:3426 [inline] path_openat+0x1cad/0x2750 fs/namei.c:3559 do_filp_open+0x1aa/0x400 fs/namei.c:3586 do_sys_openat2+0x16d/0x4d0 fs/open.c:1212 do_sys_open fs/open.c:1228 [inline] __do_sys_open fs/open.c:1236 [inline] __se_sys_open fs/open.c:1232 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1232 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+0x44/0xae The buggy address belongs to the object at ffff88801a0c0000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 3516 bytes inside of 4096-byte region [ffff88801a0c0000, ffff88801a0c1000) The buggy address belongs to the page: page:ffffea0000683000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1a0c0 head:ffffea0000683000 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010c42140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 9864, ts 191474275584, free_ts 191461998516 prep_new_page mm/page_alloc.c:2418 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369 alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191 alloc_slab_page mm/slub.c:1793 [inline] allocate_slab mm/slub.c:1930 [inline] new_slab+0x32d/0x4a0 mm/slub.c:1993 ___slab_alloc+0x918/0xfe0 mm/slub.c:3022 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109 slab_alloc_node mm/slub.c:3200 [inline] __kmalloc_node_track_caller+0x2cb/0x360 mm/slub.c:4956 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0xde/0x340 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1127 [inline] nlmsg_new include/net/netlink.h:953 [inline] rtmsg_ifinfo_build_skb+0x72/0x1a0 net/core/rtnetlink.c:3807 rtmsg_ifinfo_event net/core/rtnetlink.c:3843 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:3834 [inline] rtmsg_ifinfo+0x83/0x120 net/core/rtnetlink.c:3852 register_netdevice+0x11d0/0x1500 net/core/dev.c:9697 __ip_tunnel_create+0x398/0x5c0 net/ipv4/ip_tunnel.c:267 ip_tunnel_init_net+0x2e4/0x9d0 net/ipv4/ip_tunnel.c:1070 ops_init+0xaf/0x470 net/core/net_namespace.c:140 setup_net+0x40f/0xa30 net/core/net_namespace.c:326 copy_net_ns+0x318/0x760 net/core/net_namespace.c:470 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1338 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389 free_unref_page_prepare mm/page_alloc.c:3309 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3388 __unfreeze_partials+0x343/0x360 mm/slub.c:2527 qlink_free mm/kasan/quarantine.c:146 [inline] qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:259 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc_node mm/slub.c:3234 [inline] slab_alloc mm/slub.c:3242 [inline] __kmalloc+0x1e7/0x340 mm/slub.c:4419 kmalloc include/linux/slab.h:595 [inline] kzalloc include/linux/slab.h:724 [inline] tomoyo_encode2.part.0+0xe9/0x3a0 security/tomoyo/realpath.c:45 tomoyo_encode2 security/tomoyo/realpath.c:31 [inline] tomoyo_encode+0x28/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x186/0x620 security/tomoyo/realpath.c:288 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path2_perm+0x264/0x6b0 security/tomoyo/file.c:922 tomoyo_path_rename+0xd2/0x130 security/tomoyo/tomoyo.c:278 security_path_rename+0x1b5/0x2e0 security/security.c:1191 do_renameat2+0x472/0xc80 fs/namei.c:4764 __do_sys_rename fs/namei.c:4823 [inline] __se_sys_rename fs/namei.c:4821 [inline] __x64_sys_rename+0x7d/0xa0 fs/namei.c:4821 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 Memory state around the buggy address: ffff88801a0c0c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801a0c0d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801a0c0d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801a0c0e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801a0c0e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 74 24 je 0x26 2: 10 e8 adc %ch,%al 4: aa stos %al,%es:(%rdi) 5: fd std 6: 14 f8 adc $0xf8,%al 8: 48 89 ef mov %rbp,%rdi b: e8 f2 73 15 f8 callq 0xf8157402 10: 81 e3 00 02 00 00 and $0x200,%ebx 16: 75 25 jne 0x3d 18: 9c pushfq 19: 58 pop %rax 1a: f6 c4 02 test $0x2,%ah 1d: 75 2d jne 0x4c 1f: 48 85 db test %rbx,%rbx 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 b3 3d 08 f8 callq 0xf8083de2 <-- trapping instruction 2f: 65 8b 05 9c c0 ba 76 mov %gs:0x76bac09c(%rip),%eax # 0x76bac0d2 36: 85 c0 test %eax,%eax 38: 74 0a je 0x44 3a: 5b pop %rbx 3b: 5d pop %rbp 3c: c3 retq 3d: e8 .byte 0xe8 3e: 90 nop 3f: 2d .byte 0x2d