Hello, syzbot found the following issue on: HEAD commit: aab35c3d5112 Add linux-next specific files for 20220627 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=129388e0080000 kernel config: https://syzkaller.appspot.com/x/.config?x=6a874f114a1e4a6b dashboard link: https://syzkaller.appspot.com/bug?extid=8cdad6430c24f396f158 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10840388080000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15793588080000 Bisection is inconclusive: the first bad commit could be any of: 987f625e0799 KVM: x86: Add APIC_LVTx() macro. 4b903561ec49 KVM: x86: Add Corrected Machine Check Interrupt (CMCI) emulation to lapic. bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1395cb88080000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+8cdad6430c24f396f158@xxxxxxxxxxxxxxxxxxxxxxxxx L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details. general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef] CPU: 0 PID: 3601 Comm: syz-executor163 Not tainted 5.19.0-rc4-next-20220627-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kvm_vcpu_ioctl_x86_setup_mce arch/x86/kvm/x86.c:4899 [inline] RIP: 0010:kvm_arch_vcpu_ioctl+0x10d1/0x3d40 arch/x86/kvm/x86.c:5608 Code: 80 3c 02 00 0f 85 91 28 00 00 4d 8b ac 24 b0 02 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d bd ec 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 62 RSP: 0018:ffffc90002eaf960 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: 0000000000000006 RCX: 0000000000000000 RDX: 000000000000001d RSI: ffffffff8110c6ee RDI: 00000000000000ec RBP: ffffc90002eafd20 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 1ffffffff1fc765f R12: ffff888078e10000 R13: 0000000000000000 R14: 1ffff920005d5f36 R15: dffffc0000000000 FS: 0000555556de0300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc02f8affb8 CR3: 0000000075d2c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> kvm_vcpu_ioctl+0x973/0xf30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4200 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 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+0x46/0xb0 RIP: 0033:0x7fc02f868b69 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcc8febd88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc02f868b69 RDX: 0000000020000040 RSI: 000000004008ae9c RDI: 0000000000000005 RBP: 00007fc02f82cd10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc02f82cda0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:kvm_vcpu_ioctl_x86_setup_mce arch/x86/kvm/x86.c:4899 [inline] RIP: 0010:kvm_arch_vcpu_ioctl+0x10d1/0x3d40 arch/x86/kvm/x86.c:5608 Code: 80 3c 02 00 0f 85 91 28 00 00 4d 8b ac 24 b0 02 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d bd ec 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 62 RSP: 0018:ffffc90002eaf960 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: 0000000000000006 RCX: 0000000000000000 RDX: 000000000000001d RSI: ffffffff8110c6ee RDI: 00000000000000ec RBP: ffffc90002eafd20 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 1ffffffff1fc765f R12: ffff888078e10000 R13: 0000000000000000 R14: 1ffff920005d5f36 R15: dffffc0000000000 FS: 0000555556de0300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056206923aa70 CR3: 0000000075d2c000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 4: 0f 85 91 28 00 00 jne 0x289b a: 4d 8b ac 24 b0 02 00 mov 0x2b0(%r12),%r13 11: 00 12: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 19: fc ff df 1c: 49 8d bd ec 00 00 00 lea 0xec(%r13),%rdi 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx <-- trapping instruction 2e: 48 89 f8 mov %rdi,%rax 31: 83 e0 07 and $0x7,%eax 34: 83 c0 03 add $0x3,%eax 37: 38 d0 cmp %dl,%al 39: 7c 08 jl 0x43 3b: 84 d2 test %dl,%dl 3d: 0f .byte 0xf 3e: 85 .byte 0x85 3f: 62 .byte 0x62 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
