On Sun, Apr 23, 2023, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: d3e1ee0e67e7 Add linux-next specific files for 20230421 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=118a0520280000 > kernel config: https://syzkaller.appspot.com/x/.config?x=53c789efbcc06cf6 > dashboard link: https://syzkaller.appspot.com/bug?extid=864ac0b626794668b732 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/c558a9e1fe6a/disk-d3e1ee0e.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/2ec100a34c4c/vmlinux-d3e1ee0e.xz > kernel image: https://storage.googleapis.com/syzbot-assets/1afcd9936dc1/bzImage-d3e1ee0e.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+864ac0b626794668b732@xxxxxxxxxxxxxxxxxxxxxxxxx > > ================================================================== > BUG: KASAN: slab-use-after-free in kvm_tdp_mmu_invalidate_all_roots+0x2e3/0x370 arch/x86/kvm/mmu/tdp_mmu.c:945 > Read of size 8 at addr ffff88807c27d528 by task syz-executor.2/5817 > > CPU: 0 PID: 5817 Comm: syz-executor.2 Not tainted 6.3.0-rc7-next-20230421-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 > print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351 > print_report mm/kasan/report.c:462 [inline] > kasan_report+0x11c/0x130 mm/kasan/report.c:572 > kvm_tdp_mmu_invalidate_all_roots+0x2e3/0x370 arch/x86/kvm/mmu/tdp_mmu.c:945 > kvm_mmu_uninit_tdp_mmu+0x16/0x100 arch/x86/kvm/mmu/tdp_mmu.c:48 > kvm_mmu_uninit_vm+0x6a/0x70 arch/x86/kvm/mmu/mmu.c:6239 > kvm_arch_destroy_vm+0x369/0x490 arch/x86/kvm/x86.c:12465 > kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1313 [inline] > kvm_put_kvm+0x4da/0xae0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1347 > kvm_vcpu_release+0x51/0x70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3846 > __fput+0x27c/0xa90 fs/file_table.c:321 > task_work_run+0x16f/0x270 kernel/task_work.c:179 > resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] > exit_to_user_mode_loop kernel/entry/common.c:171 [inline] > exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204 > __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] > syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 > do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > RIP: 0033:0x7f426b83e01b > Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 > RSP: 002b:00007ffe38a35070 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 > RAX: 0000000000000000 RBX: 0000000000000008 RCX: 00007f426b83e01b > RDX: 0000000000000000 RSI: 0000001b32b3a7d4 RDI: 0000000000000007 > RBP: 00007f426b9ad980 R08: 0000000000000000 R09: 0000000075ee794b > R10: 0000000000000000 R11: 0000000000000293 R12: 000000000003d553 > R13: 00007ffe38a35170 R14: 00007ffe38a35190 R15: 0000000000000032 > </TASK> #syz fix: KVM: x86: Preserve TDP MMU roots until they are explicitly invalidated
