Messages in this thread | | | Date | Sat, 11 Aug 2018 12:09:02 -0700 | Subject | KASAN: use-after-free Write in preempt_notifier_register (2) | From | syzbot <> |
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Hello,
syzbot found the following crash on:
HEAD commit: 2b769bb85b48 Add linux-next specific files for 20180807 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=1356aef0400000 kernel config: https://syzkaller.appspot.com/x/.config?x=547d800b8773c2c5 dashboard link: https://syzkaller.appspot.com/bug?extid=d5d3b529a776503b24a2 compiler: gcc (GCC) 8.0.1 20180413 (experimental) syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=1618c464400000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=122d6672400000
IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+d5d3b529a776503b24a2@syzkaller.appspotmail.com
random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) ================================================================== BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:704 [inline] BUG: KASAN: use-after-free in preempt_notifier_register+0x1ec/0x200 kernel/sched/core.c:2460 Write of size 8 at addr ffff8801ac490050 by task syz-executor201/4333
CPU: 0 PID: 4333 Comm: syz-executor201 Not tainted 4.18.0-rc8-next-20180807+ #33 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_store8_noabort+0x17/0x20 mm/kasan/report.c:438 hlist_add_head include/linux/list.h:704 [inline] preempt_notifier_register+0x1ec/0x200 kernel/sched/core.c:2460 vcpu_load+0x27/0x40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:163 vmx_free_vcpu_nested arch/x86/kvm/vmx.c:10658 [inline] vmx_free_vcpu+0x194/0x300 arch/x86/kvm/vmx.c:10672 kvm_arch_vcpu_free arch/x86/kvm/x86.c:8387 [inline] kvm_free_vcpus arch/x86/kvm/x86.c:8836 [inline] kvm_arch_destroy_vm+0x365/0x7c0 arch/x86/kvm/x86.c:8933 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+0x376/0x8a0 fs/file_table.c:279 ____fput+0x15/0x20 fs/file_table.c:312 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x1b25/0x2760 kernel/exit.c:869 do_group_exit+0x177/0x440 kernel/exit.c:972 __do_sys_exit_group kernel/exit.c:983 [inline] __se_sys_exit_group kernel/exit.c:981 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:981 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x43ece8 Code: Bad RIP value. RSP: 002b:00007ffd3f933c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ece8 RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00000000004be5a8 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000006d0180 R14: 0000000000000000 R15: 0000000000000000
Allocated by task 4333: 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/0x760 mm/slab.c:3554 kmem_cache_zalloc include/linux/slab.h:697 [inline] vmx_create_vcpu+0xcf/0x28b0 arch/x86/kvm/vmx.c:10682 kvm_arch_vcpu_create+0xe5/0x220 arch/x86/kvm/x86.c:8401 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 4333: 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+0x86/0x2d0 mm/slab.c:3756 vmx_free_vcpu+0x26b/0x300 arch/x86/kvm/vmx.c:10676 kvm_arch_vcpu_free arch/x86/kvm/x86.c:8387 [inline] kvm_free_vcpus arch/x86/kvm/x86.c:8836 [inline] kvm_arch_destroy_vm+0x365/0x7c0 arch/x86/kvm/x86.c:8933 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+0x376/0x8a0 fs/file_table.c:279 ____fput+0x15/0x20 fs/file_table.c:312 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x1b25/0x2760 kernel/exit.c:869 do_group_exit+0x177/0x440 kernel/exit.c:972 __do_sys_exit_group kernel/exit.c:983 [inline] __se_sys_exit_group kernel/exit.c:981 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:981 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 ffff8801ac490040 which belongs to the cache kvm_vcpu of size 23808 The buggy address is located 16 bytes inside of 23808-byte region [ffff8801ac490040, ffff8801ac495d40) The buggy address belongs to the page: page:ffffea0006b12400 count:1 mapcount:0 mapping:ffff8801d5297a80 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffff8801d528f448 ffffea0006b2aa08 ffff8801d5297a80 raw: 0000000000000000 ffff8801ac490040 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address: ffff8801ac48ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8801ac48ff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff > ffff8801ac490000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8801ac490080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801ac490100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================
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