================================================================== BUG: KASAN: use-after-free in __list_del_entry_valid+0xe6/0xf5 lib/list_debug.c:51 Read of size 8 at addr ffff88808b1d7128 by task syz-executor.2/14865 CPU: 0 PID: 14865 Comm: syz-executor.2 Not tainted 5.2.0-rc3-next-20190606 #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 __list_del_entry_valid+0xe6/0xf5 lib/list_debug.c:51 __list_del_entry include/linux/list.h:117 [inline] list_del include/linux/list.h:125 [inline] unregister_shrinker+0xb2/0x2e0 mm/vmscan.c:443 deactivate_locked_super+0x73/0x100 fs/super.c:330 deactivate_super fs/super.c:362 [inline] deactivate_super+0x1b2/0x1d0 fs/super.c:358 cleanup_mnt+0xbf/0x160 fs/namespace.c:1120 __cleanup_mnt+0x16/0x20 fs/namespace.c:1127 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:168 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x58e/0x680 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459279 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f16afb5fc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000459279 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000280 RBP: 000000000075bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f16afb606d4 R13: 00000000004c84d8 R14: 00000000004dec50 R15: 00000000ffffffff Allocated by task 14819: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503 __do_kmalloc mm/slab.c:3654 [inline] __kmalloc+0x15c/0x740 mm/slab.c:3663 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:742 [inline] ops_init+0xff/0x410 net/core/net_namespace.c:120 setup_net+0x2d3/0x740 net/core/net_namespace.c:316 copy_net_ns+0x1df/0x340 net/core/net_namespace.c:439 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x444/0x980 kernel/fork.c:2717 __do_sys_unshare kernel/fork.c:2785 [inline] __se_sys_unshare kernel/fork.c:2783 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2783 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 14819: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3426 [inline] kfree+0x106/0x2a0 mm/slab.c:3753 ops_init+0xd1/0x410 net/core/net_namespace.c:135 setup_net+0x2d3/0x740 net/core/net_namespace.c:316 copy_net_ns+0x1df/0x340 net/core/net_namespace.c:439 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x444/0x980 kernel/fork.c:2717 __do_sys_unshare kernel/fork.c:2785 [inline] __se_sys_unshare kernel/fork.c:2783 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2783 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88808b1d6dc0 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 872 bytes inside of 1024-byte region [ffff88808b1d6dc0, ffff88808b1d71c0) The buggy address belongs to the page: page:ffffea00022c7580 refcount:1 mapcount:0 mapping:ffff8880aa400ac0 index:0xffff88808b1d64c0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea000284f208 ffffea000231df08 ffff8880aa400ac0 raw: ffff88808b1d64c0 ffff88808b1d6040 0000000100000005 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808b1d7000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808b1d7080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808b1d7100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808b1d7180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88808b1d7200: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ==================================================================