Hello, kernel test robot noticed "UBSAN:shift-out-of-bounds_in_arch/x86/kvm#h" on: commit: 1635eb4564804d324e91d78e8e5ed206e006e3a6 ("[PATCH 1/2] KVM: x86: Check hypercall's exit to userspace generically") url: https://github.com/intel-lab-lkp/linux/commits/Binbin-Wu/KVM-x86-Check-hypercall-s-exit-to-userspace-generically/20240708-172555 patch link: https://lore.kernel.org/all/20240708092150.1799371-2-binbin.wu@xxxxxxxxxxxxxxx/ patch subject: [PATCH 1/2] KVM: x86: Check hypercall's exit to userspace generically in testcase: kvm-unit-tests-qemu version: with following parameters: compiler: gcc-13 test machine: 128 threads 2 sockets Intel(R) Xeon(R) Platinum 8358 CPU @ 2.60GHz (Ice Lake) with 128G memory (please refer to attached dmesg/kmsg for entire log/backtrace) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-lkp/202407242159.893be500-oliver.sang@xxxxxxxxx [ 414.980354][T21255] ------------[ cut here ]------------ [ 414.989024][T21255] UBSAN: shift-out-of-bounds in arch/x86/kvm/x86.h:552:47 [ 415.001167][T21255] shift exponent 4294967295 is too large for 32-bit type 'int' [ 415.011803][T21255] CPU: 107 PID: 21255 Comm: qemu-system-x86 Not tainted 6.10.0-rc2-00186-g1635eb456480 #1 [ 415.024716][T21255] Call Trace: [ 415.030982][T21255] <TASK> [415.036836][T21255] dump_stack_lvl (lib/dump_stack.c:117) [415.044268][T21255] __ubsan_handle_shift_out_of_bounds (lib/ubsan.c:232 lib/ubsan.c:468) [415.053610][T21255] kvm_emulate_hypercall.cold (include/trace/events/kvm.h:213 (discriminator 6)) kvm [415.063097][T21255] ? __pfx_kvm_emulate_hypercall (arch/x86/kvm/x86.c:10206) kvm [415.073104][T21255] ? __vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:6469) kvm_intel [415.082284][T21255] vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:6632 (discriminator 1)) kvm_intel [415.090893][T21255] vcpu_enter_guest+0x130f/0x3350 kvm [415.100855][T21255] ? vmx_segment_cache_test_set (arch/x86/include/asm/bitops.h:206 (discriminator 1) arch/x86/include/asm/bitops.h:238 (discriminator 1) include/asm-generic/bitops/instrumented-non-atomic.h:142 (discriminator 1) arch/x86/kvm/vmx/../kvm_cache_regs.h:56 (discriminator 1) arch/x86/kvm/vmx/vmx.c:825 (discriminator 1)) kvm_intel [415.110593][T21255] ? __pfx_vcpu_enter_guest+0x10/0x10 kvm [415.120837][T21255] ? vmx_read_guest_seg_ar (arch/x86/kvm/vmx/vmx.c:865 (discriminator 1)) kvm_intel [415.130124][T21255] ? skip_emulated_instruction (arch/x86/kvm/vmx/vmx.c:1775) kvm_intel [415.139821][T21255] ? __pfx_skip_emulated_instruction (arch/x86/kvm/vmx/vmx.c:1715) kvm_intel [415.149853][T21255] ? __pfx_kvm_get_linear_rip (arch/x86/kvm/x86.c:13256) kvm [415.159211][T21255] vcpu_run (arch/x86/kvm/x86.c:11311) kvm [415.167028][T21255] kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:11537) kvm [415.176327][T21255] ? __pfx_do_vfs_ioctl (fs/ioctl.c:805) [415.184065][T21255] kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4440) kvm [415.192450][T21255] ? __pfx_kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4394) kvm [415.201351][T21255] ? down_read_trylock (arch/x86/include/asm/atomic64_64.h:20 include/linux/atomic/atomic-arch-fallback.h:2629 include/linux/atomic/atomic-long.h:79 include/linux/atomic/atomic-instrumented.h:3224 kernel/locking/rwsem.c:176 kernel/locking/rwsem.c:181 kernel/locking/rwsem.c:1288 kernel/locking/rwsem.c:1565) [415.209117][T21255] ? __fget_light (fs/file.c:1154) [415.216411][T21255] ? fput (arch/x86/include/asm/atomic64_64.h:61 (discriminator 1) include/linux/atomic/atomic-arch-fallback.h:4404 (discriminator 1) include/linux/atomic/atomic-long.h:1571 (discriminator 1) include/linux/atomic/atomic-instrumented.h:4540 (discriminator 1) fs/file_table.c:473 (discriminator 1)) [415.222864][T21255] ? __fget_light (fs/file.c:1154) [415.230119][T21255] __x64_sys_ioctl (fs/ioctl.c:51 fs/ioctl.c:907 fs/ioctl.c:893 fs/ioctl.c:893) [415.237407][T21255] do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) [415.244400][T21255] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) [ 415.252801][T21255] RIP: 0033:0x7f12912f8c5b [ 415.259801][T21255] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 All code ======== 0: 00 48 89 add %cl,-0x77(%rax) 3: 44 24 18 rex.R and $0x18,%al 6: 31 c0 xor %eax,%eax 8: 48 8d 44 24 60 lea 0x60(%rsp),%rax d: c7 04 24 10 00 00 00 movl $0x10,(%rsp) 14: 48 89 44 24 08 mov %rax,0x8(%rsp) 19: 48 8d 44 24 20 lea 0x20(%rsp),%rax 1e: 48 89 44 24 10 mov %rax,0x10(%rsp) 23: b8 10 00 00 00 mov $0x10,%eax 28: 0f 05 syscall 2a:* 89 c2 mov %eax,%edx <-- trapping instruction 2c: 3d 00 f0 ff ff cmp $0xfffff000,%eax 31: 77 1c ja 0x4f 33: 48 8b 44 24 18 mov 0x18(%rsp),%rax 38: 64 fs 39: 48 rex.W 3a: 2b .byte 0x2b 3b: 04 25 add $0x25,%al 3d: 28 00 sub %al,(%rax) ... Code starting with the faulting instruction =========================================== 0: 89 c2 mov %eax,%edx 2: 3d 00 f0 ff ff cmp $0xfffff000,%eax 7: 77 1c ja 0x25 9: 48 8b 44 24 18 mov 0x18(%rsp),%rax e: 64 fs f: 48 rex.W 10: 2b .byte 0x2b 11: 04 25 add $0x25,%al 13: 28 00 sub %al,(%rax) ... [ 415.282007][T21255] RSP: 002b:00007f128e7ff5e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 415.293025][T21255] RAX: ffffffffffffffda RBX: 000055cecae83b00 RCX: 00007f12912f8c5b [ 415.303708][T21255] RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 000000000000000c [ 415.314228][T21255] RBP: 000000000000ae80 R08: 0000000000000000 R09: 0000000000000000 [ 415.324787][T21255] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 415.335326][T21255] R13: 0000000000000001 R14: 00000000000003f8 R15: 0000000000000000 [ 415.345809][T21255] </TASK> [ 415.351386][T21255] ---[ end trace ]--- The kernel config and materials to reproduce are available at: https://download.01.org/0day-ci/archive/20240724/202407242159.893be500-oliver.sang@xxxxxxxxx -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki