audit: type=1400 audit(1536270429.047:7): avc: denied { map } for pid=4838 comm="syz-executor268" path="/root/syz-executor268425583" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html for details. ================================================================== BUG: KASAN: use-after-free in __fire_sched_out_preempt_notifiers kernel/sched/core.c:2497 [inline] BUG: KASAN: use-after-free in fire_sched_out_preempt_notifiers kernel/sched/core.c:2505 [inline] BUG: KASAN: use-after-free in prepare_task_switch kernel/sched/core.c:2611 [inline] BUG: KASAN: use-after-free in context_switch kernel/sched/core.c:2790 [inline] BUG: KASAN: use-after-free in __schedule+0xf54/0x1df0 kernel/sched/core.c:3473 Read of size 8 at addr ffff8801c8ff0058 by task syz-executor268/4838 CPU: 1 PID: 4838 Comm: syz-executor268 Not tainted 4.19.0-rc2+ #3 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+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 __fire_sched_out_preempt_notifiers kernel/sched/core.c:2497 [inline] fire_sched_out_preempt_notifiers kernel/sched/core.c:2505 [inline] prepare_task_switch kernel/sched/core.c:2611 [inline] context_switch kernel/sched/core.c:2790 [inline] __schedule+0xf54/0x1df0 kernel/sched/core.c:3473 preempt_schedule_common+0x22/0x60 kernel/sched/core.c:3597 _cond_resched+0x1d/0x30 kernel/sched/core.c:4963 __wait_for_common kernel/sched/completion.c:99 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0xa5/0x8d0 kernel/sched/completion.c:136 __synchronize_srcu+0x189/0x240 kernel/rcu/srcutree.c:934 synchronize_srcu_expedited kernel/rcu/srcutree.c:959 [inline] synchronize_srcu+0x335/0x56f kernel/rcu/srcutree.c:1010 kvm_page_track_unregister_notifier+0x17d/0x250 arch/x86/kvm/page_track.c:214 kvm_mmu_uninit_vm+0x1c/0x20 arch/x86/kvm/mmu.c:5439 kvm_arch_destroy_vm+0x5f2/0x7c0 arch/x86/kvm/x86.c:8969 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:752 [inline] kvm_put_kvm+0x73f/0x1060 arch/x86/kvm/../../../virt/kvm/kvm_main.c:773 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:784 __fput+0x38a/0xa40 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x1ae4/0x26e0 kernel/exit.c:867 do_group_exit+0x177/0x440 kernel/exit.c:970 __do_sys_exit_group kernel/exit.c:981 [inline] __se_sys_exit_group kernel/exit.c:979 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:979 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x43f028 Code: Bad RIP value. RSP: 002b:00007ffd2784e208 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043f028 RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00000000004c08e8 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 4838: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x710 mm/slab.c:3554 kmem_cache_zalloc include/linux/slab.h:697 [inline] vmx_create_vcpu+0xcf/0x2830 arch/x86/kvm/vmx.c:10954 kvm_arch_vcpu_create+0xe5/0x220 arch/x86/kvm/x86.c:8434 kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:2476 [inline] kvm_vm_ioctl+0x488/0x1d80 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2977 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 4838: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x280 mm/slab.c:3756 vmx_free_vcpu+0x26b/0x300 arch/x86/kvm/vmx.c:10948 kvm_arch_vcpu_free arch/x86/kvm/x86.c:8420 [inline] kvm_free_vcpus arch/x86/kvm/x86.c:8870 [inline] kvm_arch_destroy_vm+0x365/0x7c0 arch/x86/kvm/x86.c:8967 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:752 [inline] kvm_put_kvm+0x73f/0x1060 arch/x86/kvm/../../../virt/kvm/kvm_main.c:773 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:784 __fput+0x38a/0xa40 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x1ae4/0x26e0 kernel/exit.c:867 do_group_exit+0x177/0x440 kernel/exit.c:970 __do_sys_exit_group kernel/exit.c:981 [inline] __se_sys_exit_group kernel/exit.c:979 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:979 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801c8ff0040 which belongs to the cache kvm_vcpu of size 23872 The buggy address is located 24 bytes inside of 23872-byte region [ffff8801c8ff0040, ffff8801c8ff5d80) The buggy address belongs to the page: page:ffffea000723fc00 count:1 mapcount:0 mapping:ffff8801d4473dc0 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffff8801d4c39048 ffff8801d4c39048 ffff8801d4473dc0 raw: 0000000000000000 ffff8801c8ff0040 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c8feff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8801c8feff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8801c8ff0000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8801c8ff0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c8ff0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================