================================================================== BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:71 [inline] BUG: KASAN: use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] BUG: KASAN: use-after-free in ip6mr_sk_done+0x139/0x400 net/ipv6/ip6mr.c:1604 Read of size 4 at addr ffff88803bc82888 by task syz-executor.5/11749 CPU: 0 PID: 11749 Comm: syz-executor.5 Not tainted 6.0.0-syzkaller-02743-g1d2d941bc140 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 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 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] ip6mr_sk_done+0x139/0x400 net/ipv6/ip6mr.c:1604 rawv6_close+0x58/0x80 net/ipv6/raw.c:1167 inet_release+0x12e/0x270 net/ipv4/af_inet.c:428 inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:482 __sock_release net/socket.c:650 [inline] sock_release+0x87/0x1b0 net/socket.c:678 inet_ctl_sock_destroy include/net/inet_common.h:71 [inline] igmp6_net_exit+0x6b/0x170 net/ipv6/mcast.c:3167 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:162 setup_net+0x7fb/0xc50 net/core/net_namespace.c:348 copy_net_ns+0x318/0x760 net/core/net_namespace.c:471 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178 copy_process+0x304d/0x7090 kernel/fork.c:2257 kernel_clone+0xe7/0xab0 kernel/fork.c:2671 __do_sys_clone+0xba/0x100 kernel/fork.c:2805 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 RIP: 0033:0x7fce3d08a5a9 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fce3e1da118 EFLAGS: 00000202 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007fce3d1ac050 RCX: 00007fce3d08a5a9 RDX: 0000000020000040 RSI: 0000000000000000 RDI: 0000000074809480 RBP: 00007fce3d0e5580 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007fffdbd9174f R14: 00007fce3e1da300 R15: 0000000000022000 Allocated by task 11749: 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 kmemdup+0x23/0x50 mm/util.c:129 kmemdup include/linux/fortify-string.h:565 [inline] addrconf_init_net+0x1be/0x870 net/ipv6/addrconf.c:7161 ops_init+0xaf/0x470 net/core/net_namespace.c:134 setup_net+0x5d1/0xc50 net/core/net_namespace.c:325 copy_net_ns+0x318/0x760 net/core/net_namespace.c:471 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178 copy_process+0x304d/0x7090 kernel/fork.c:2257 kernel_clone+0xe7/0xab0 kernel/fork.c:2671 __do_sys_clone+0xba/0x100 kernel/fork.c:2805 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 11749: 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:1759 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1785 slab_free mm/slub.c:3539 [inline] kfree+0xe2/0x580 mm/slub.c:4567 addrconf_init_net+0x649/0x870 net/ipv6/addrconf.c:7219 ops_init+0xaf/0x470 net/core/net_namespace.c:134 setup_net+0x5d1/0xc50 net/core/net_namespace.c:325 copy_net_ns+0x318/0x760 net/core/net_namespace.c:471 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178 copy_process+0x304d/0x7090 kernel/fork.c:2257 kernel_clone+0xe7/0xab0 kernel/fork.c:2671 __do_sys_clone+0xba/0x100 kernel/fork.c:2805 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 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 kvfree_call_rcu+0x74/0x8f0 kernel/rcu/tree.c:3341 drop_sysctl_table+0x3c0/0x4e0 fs/proc/proc_sysctl.c:1716 unregister_sysctl_table fs/proc/proc_sysctl.c:1754 [inline] unregister_sysctl_table+0xc0/0x190 fs/proc/proc_sysctl.c:1729 mpls_dev_sysctl_unregister net/mpls/af_mpls.c:1441 [inline] mpls_dev_notify+0x5cb/0x9b0 net/mpls/af_mpls.c:1653 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] unregister_netdevice_many+0xa69/0x1980 net/core/dev.c:10843 unregister_netdevice_queue+0x2dd/0x3c0 net/core/dev.c:10774 unregister_netdevice include/linux/netdevice.h:3032 [inline] __tun_detach+0x111d/0x1480 drivers/net/tun.c:684 tun_detach drivers/net/tun.c:701 [inline] tun_chr_close+0xc4/0x180 drivers/net/tun.c:3458 __fput+0x277/0x9d0 fs/file_table.c:320 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to 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 kvfree_call_rcu+0x74/0x8f0 kernel/rcu/tree.c:3341 drop_sysctl_table+0x3c0/0x4e0 fs/proc/proc_sysctl.c:1716 unregister_sysctl_table fs/proc/proc_sysctl.c:1754 [inline] unregister_sysctl_table+0xc0/0x190 fs/proc/proc_sysctl.c:1729 mptcp_pernet_del_table net/mptcp/ctrl.c:172 [inline] mptcp_net_exit+0x149/0x2b0 net/mptcp/ctrl.c:202 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:162 setup_net+0x7fb/0xc50 net/core/net_namespace.c:348 copy_net_ns+0x318/0x760 net/core/net_namespace.c:471 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178 copy_process+0x304d/0x7090 kernel/fork.c:2257 kernel_clone+0xe7/0xab0 kernel/fork.c:2671 __do_sys_clone+0xba/0x100 kernel/fork.c:2805 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 ffff88803bc82800 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 136 bytes inside of 256-byte region [ffff88803bc82800, ffff88803bc82900) The buggy address belongs to the physical page: page:ffffea0000ef2080 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3bc82 head:ffffea0000ef2080 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea000120f680 dead000000000002 ffff888011841b40 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5830, tgid 5824 (syz-executor.2), ts 336698249191, free_ts 335461758037 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:5549 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1829 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1974 new_slab mm/slub.c:2034 [inline] ___slab_alloc+0x84f/0xe80 mm/slub.c:3036 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3123 slab_alloc_node mm/slub.c:3214 [inline] slab_alloc mm/slub.c:3256 [inline] __kmalloc+0x32b/0x340 mm/slub.c:4425 kmalloc include/linux/slab.h:605 [inline] kzalloc include/linux/slab.h:733 [inline] new_dir fs/proc/proc_sysctl.c:978 [inline] get_subdir fs/proc/proc_sysctl.c:1022 [inline] __register_sysctl_table+0x9eb/0x10a0 fs/proc/proc_sysctl.c:1373 neigh_sysctl_register+0x2c8/0x5e0 net/core/neighbour.c:3852 addrconf_sysctl_register+0xb6/0x1d0 net/ipv6/addrconf.c:7126 ipv6_add_dev+0xade/0x1390 net/ipv6/addrconf.c:450 addrconf_notify+0x6f9/0x1c10 net/ipv6/addrconf.c:3528 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] register_netdevice+0x10bb/0x1670 net/core/dev.c:10086 register_netdev+0x2d/0x50 net/core/dev.c:10179 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 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2553 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:447 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slub.c:3248 [inline] slab_alloc mm/slub.c:3256 [inline] __kmalloc+0x28a/0x340 mm/slub.c:4425 kmalloc include/linux/slab.h:605 [inline] tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x140 security/security.c:1345 vfs_getattr fs/stat.c:158 [inline] vfs_statx+0x16e/0x430 fs/stat.c:233 vfs_fstatat+0x8c/0xb0 fs/stat.c:267 __do_sys_newfstatat+0x94/0x120 fs/stat.c:437 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 Memory state around the buggy address: ffff88803bc82780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88803bc82800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803bc82880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803bc82900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88803bc82980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================