kernel.git/arch/x86, branch linux-6.0.y

x86/bugs: Flush IBP in ib_prctl_set()

2023-01-12T11:00:45Z

commit a664ec9158eeddd75121d39c9a0758016097fa96 upstream. We missed the window between the TIF flag update and the next reschedule. Signed-off-by: Rodrigo Branco Reviewed-by: Borislav Petkov (AMD) Signed-off-by: Ingo Molnar Cc: Signed-off-by: Greg Kroah-Hartman

x86/kexec: Fix double-free of elf header buffer

2023-01-12T11:00:45Z

commit d00dd2f2645dca04cf399d8fc692f3f69b6dd996 upstream. After b3e34a47f989 ("x86/kexec: fix memory leak of elf header buffer"), freeing image->elf_headers in the error path of crash_load_segments() is not needed because kimage_file_post_load_cleanup() will take care of that later. And not clearing it could result in a double-free. Drop the superfluous vfree() call at the error path of crash_load_segments(). Fixes: b3e34a47f989 ("x86/kexec: fix memory leak of elf header buffer") Signed-off-by: Takashi Iwai Signed-off-by: Borislav Petkov (AMD) Acked-by: Baoquan He Acked-by: Vlastimil Babka Cc: Link: https://lore.kernel.org/r/20221122115122.13937-1-tiwai@suse.de Signed-off-by: Greg Kroah-Hartman

x86/kprobes: Fix optprobe optimization check with CONFIG_RETHUNK

2023-01-07T10:15:51Z

commit 63dc6325ff41ee9e570bde705ac34a39c5dbeb44 upstream. Since the CONFIG_RETHUNK and CONFIG_SLS will use INT3 for stopping speculative execution after function return, kprobe jump optimization always fails on the functions with such INT3 inside the function body. (It already checks the INT3 padding between functions, but not inside the function) To avoid this issue, as same as kprobes, check whether the INT3 comes from kgdb or not, and if so, stop decoding and make it fail. The other INT3 will come from CONFIG_RETHUNK/CONFIG_SLS and those can be treated as a one-byte instruction. Fixes: e463a09af2f0 ("x86: Add straight-line-speculation mitigation") Suggested-by: Peter Zijlstra Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Peter Zijlstra (Intel) Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/167146051929.1374301.7419382929328081706.stgit@devnote3 Signed-off-by: Greg Kroah-Hartman

x86/kprobes: Fix kprobes instruction boudary check with CONFIG_RETHUNK

2023-01-07T10:15:51Z

commit 1993bf97992df2d560287f3c4120eda57426843d upstream. Since the CONFIG_RETHUNK and CONFIG_SLS will use INT3 for stopping speculative execution after RET instruction, kprobes always failes to check the probed instruction boundary by decoding the function body if the probed address is after such sequence. (Note that some conditional code blocks will be placed after function return, if compiler decides it is not on the hot path.) This is because kprobes expects kgdb puts the INT3 as a software breakpoint and it will replace the original instruction. But these INT3 are not such purpose, it doesn't need to recover the original instruction. To avoid this issue, kprobes checks whether the INT3 is owned by kgdb or not, and if so, stop decoding and make it fail. The other INT3 will come from CONFIG_RETHUNK/CONFIG_SLS and those can be treated as a one-byte instruction. Fixes: e463a09af2f0 ("x86: Add straight-line-speculation mitigation") Suggested-by: Peter Zijlstra Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Peter Zijlstra (Intel) Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/167146051026.1374301.392728975473572291.stgit@devnote3 Signed-off-by: Greg Kroah-Hartman

ftrace/x86: Add back ftrace_expected for ftrace bug reports

2023-01-07T10:15:51Z

commit fd3dc56253acbe9c641a66d312d8393cd55eb04c upstream. After someone reported a bug report with a failed modification due to the expected value not matching what was found, it came to my attention that the ftrace_expected is no longer set when that happens. This makes for debugging the issue a bit more difficult. Set ftrace_expected to the expected code before calling ftrace_bug, so that it shows what was expected and why it failed. Link: https://lore.kernel.org/all/CA+wXwBQ-VhK+hpBtYtyZP-NiX4g8fqRRWithFOHQW-0coQ3vLg@mail.gmail.com/ Link: https://lore.kernel.org/linux-trace-kernel/20221209105247.01d4e51d@gandalf.local.home Cc: Masami Hiramatsu Cc: Andrew Morton Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: "x86@kernel.org" Cc: Borislav Petkov Cc: Ingo Molnar Cc: stable@vger.kernel.org Fixes: 768ae4406a5c ("x86/ftrace: Use text_poke()") Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

x86/microcode/intel: Do not retry microcode reloading on the APs

2023-01-07T10:15:51Z

commit be1b670f61443aa5d0d01782e9b8ea0ee825d018 upstream. The retries in load_ucode_intel_ap() were in place to support systems with mixed steppings. Mixed steppings are no longer supported and there is only one microcode image at a time. Any retries will simply reattempt to apply the same image over and over without making progress. [ bp: Zap the circumstantial reasoning from the commit message. ] Fixes: 06b8534cb728 ("x86/microcode: Rework microcode loading") Signed-off-by: Ashok Raj Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20221129210832.107850-3-ashok.raj@intel.com Signed-off-by: Greg Kroah-Hartman

KVM: nVMX: Properly expose ENABLE_USR_WAIT_PAUSE control to L1

2023-01-07T10:15:51Z

commit 31de69f4eea77b28a9724b3fa55aae104fc91fc7 upstream. Set ENABLE_USR_WAIT_PAUSE in KVM's supported VMX MSR configuration if the feature is supported in hardware and enabled in KVM's base, non-nested configuration, i.e. expose ENABLE_USR_WAIT_PAUSE to L1 if it's supported. This fixes a bug where saving/restoring, i.e. migrating, a vCPU will fail if WAITPKG (the associated CPUID feature) is enabled for the vCPU, and obviously allows L1 to enable the feature for L2. KVM already effectively exposes ENABLE_USR_WAIT_PAUSE to L1 by stuffing the allowed-1 control ina vCPU's virtual MSR_IA32_VMX_PROCBASED_CTLS2 when updating secondary controls in response to KVM_SET_CPUID(2), but (a) that depends on flawed code (KVM shouldn't touch VMX MSRs in response to CPUID updates) and (b) runs afoul of vmx_restore_control_msr()'s restriction that the guest value must be a strict subset of the supported host value. Although no past commit explicitly enabled nested support for WAITPKG, doing so is safe and functionally correct from an architectural perspective as no additional KVM support is needed to virtualize TPAUSE, UMONITOR, and UMWAIT for L2 relative to L1, and KVM already forwards VM-Exits to L1 as necessary (commit bf653b78f960, "KVM: vmx: Introduce handle_unexpected_vmexit and handle WAITPKG vmexit"). Note, KVM always keeps the hosts MSR_IA32_UMWAIT_CONTROL resident in hardware, i.e. always runs both L1 and L2 with the host's power management settings for TPAUSE and UMWAIT. See commit bf09fb6cba4f ("KVM: VMX: Stop context switching MSR_IA32_UMWAIT_CONTROL") for more details. Fixes: e69e72faa3a0 ("KVM: x86: Add support for user wait instructions") Cc: stable@vger.kernel.org Reported-by: Aaron Lewis Reported-by: Yu Zhang Signed-off-by: Sean Christopherson Reviewed-by: Jim Mattson Message-Id: <20221213062306.667649-2-seanjc@google.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

KVM: x86: fix APICv/x2AVIC disabled when vm reboot by itself

2023-01-07T10:15:51Z

commit ef40757743b47cc95de9b4ed41525c94f8dc73d9 upstream. When a VM reboots itself, the reset process will result in an ioctl(KVM_SET_LAPIC, ...) to disable x2APIC mode and set the xAPIC id of the vCPU to its default value, which is the vCPU id. That will be handled in KVM as follows: kvm_vcpu_ioctl_set_lapic kvm_apic_set_state kvm_lapic_set_base => disable X2APIC mode kvm_apic_state_fixup kvm_lapic_xapic_id_updated kvm_xapic_id(apic) != apic->vcpu->vcpu_id kvm_set_apicv_inhibit(APICV_INHIBIT_REASON_APIC_ID_MODIFIED) memcpy(vcpu->arch.apic->regs, s->regs, sizeof(*s)) => update APIC_ID When kvm_apic_set_state invokes kvm_lapic_set_base to disable x2APIC mode, the old 32-bit x2APIC id is still present rather than the 8-bit xAPIC id. kvm_lapic_xapic_id_updated will set the APICV_INHIBIT_REASON_APIC_ID_MODIFIED bit and disable APICv/x2AVIC. Instead, kvm_lapic_xapic_id_updated must be called after APIC_ID is changed. In fact, this fixes another small issue in the code in that potential changes to a vCPU's xAPIC ID need not be tracked for KVM_GET_LAPIC. Fixes: 3743c2f02517 ("KVM: x86: inhibit APICv/AVIC on changes to APIC ID or APIC base") Signed-off-by: Yuan ZhaoXiong Message-Id: <1669984574-32692-1-git-send-email-yuanzhaoxiong@baidu.com> Cc: stable@vger.kernel.org Reported-by: Alejandro Jimenez Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

KVM: nVMX: Inject #GP, not #UD, if "generic" VMXON CR0/CR4 check fails

2023-01-07T10:15:50Z

commit 9cc409325ddd776f6fd6293d5ce93ce1248af6e4 upstream. Inject #GP for if VMXON is attempting with a CR0/CR4 that fails the generic "is CRx valid" check, but passes the CR4.VMXE check, and do the generic checks _after_ handling the post-VMXON VM-Fail. The CR4.VMXE check, and all other #UD cases, are special pre-conditions that are enforced prior to pivoting on the current VMX mode, i.e. occur before interception if VMXON is attempted in VMX non-root mode. All other CR0/CR4 checks generate #GP and effectively have lower priority than the post-VMXON check. Per the SDM: IF (register operand) or (CR0.PE = 0) or (CR4.VMXE = 0) or ... THEN #UD; ELSIF not in VMX operation THEN IF (CPL > 0) or (in A20M mode) or (the values of CR0 and CR4 are not supported in VMX operation) THEN #GP(0); ELSIF in VMX non-root operation THEN VMexit; ELSIF CPL > 0 THEN #GP(0); ELSE VMfail("VMXON executed in VMX root operation"); FI; which, if re-written without ELSIF, yields: IF (register operand) or (CR0.PE = 0) or (CR4.VMXE = 0) or ... THEN #UD IF in VMX non-root operation THEN VMexit; IF CPL > 0 THEN #GP(0) IF in VMX operation THEN VMfail("VMXON executed in VMX root operation"); IF (in A20M mode) or (the values of CR0 and CR4 are not supported in VMX operation) THEN #GP(0); Note, KVM unconditionally forwards VMXON VM-Exits that occur in L2 to L1, i.e. there is no need to check the vCPU is not in VMX non-root mode. Add a comment to explain why unconditionally forwarding such exits is functionally correct. Reported-by: Eric Li Fixes: c7d855c2aff2 ("KVM: nVMX: Inject #UD if VMXON is attempted with incompatible CR0/CR4") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20221006001956.329314-1-seanjc@google.com Signed-off-by: Greg Kroah-Hartman

KVM: VMX: Resume guest immediately when injecting #GP on ECREATE

2023-01-07T10:15:50Z

commit eb3992e833d3a17f9b0a3e0371d0b1d3d566f740 upstream. Resume the guest immediately when injecting a #GP on ECREATE due to an invalid enclave size, i.e. don't attempt ECREATE in the host. The #GP is a terminal fault, e.g. skipping the instruction if ECREATE is successful would result in KVM injecting #GP on the instruction following ECREATE. Fixes: 70210c044b4e ("KVM: VMX: Add SGX ENCLS[ECREATE] handler to enforce CPUID restrictions") Cc: stable@vger.kernel.org Cc: Kai Huang Signed-off-by: Sean Christopherson Reviewed-by: Kai Huang Link: https://lore.kernel.org/r/20220930233132.1723330-1-seanjc@google.com Signed-off-by: Greg Kroah-Hartman