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* KVM: vmx: hyper-v: don't pass EPT configuration info to ↵Vitaly Kuznetsov2018-10-131-1/+5
| | | | | | | | | | | | | | | | | | vmx_hv_remote_flush_tlb() I'm observing random crashes in multi-vCPU L2 guests running on KVM on Hyper-V. I bisected the issue to the commit 877ad952be3d ("KVM: vmx: Add tlb_remote_flush callback support"). Hyper-V TLFS states: "AddressSpace specifies an address space ID (an EPT PML4 table pointer)" So apparently, Hyper-V doesn't expect us to pass naked EPTP, only PML4 pointer should be used. Strip off EPT configuration information before calling into vmx_hv_remote_flush_tlb(). Fixes: 877ad952be3d ("KVM: vmx: Add tlb_remote_flush callback support") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* Merge tag 'kvmarm-fixes-for-4.19-2' of ↵Paolo Bonzini2018-10-091-4/+4
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master KVM/arm fixes for 4.19, take #2 - Correctly order GICv3 SGI registers in the cp15 array
| * ARM: KVM: Correctly order SGI register entries in the cp15 arrayMarc Zyngier2018-10-091-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | The ICC_ASGI1R and ICC_SGI0R register entries in the cp15 array are not correctly ordered, leading to a BUG() at boot time. Move them to their natural location. Fixes: 3e8a8a50c7ef ("KVM: arm: vgic-v3: Add support for ICC_SGI0R and ICC_ASGI1R accesses") Reported-by: Florian Fainelli <f.fainelli@gmail.com> Tested-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* | KVM: x86: support CONFIG_KVM_AMD=y with CONFIG_CRYPTO_DEV_CCP_DD=mPaolo Bonzini2018-10-091-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SEV requires access to the AMD cryptographic device APIs, and this does not work when KVM is builtin and the crypto driver is a module. Actually the Kconfig conditions for CONFIG_KVM_AMD_SEV try to disable SEV in that case, but it does not work because the actual crypto calls are not culled, only sev_hardware_setup() is. This patch adds two CONFIG_KVM_AMD_SEV checks that gate all the remaining SEV code; it fixes this particular configuration, and drops 5 KiB of code when CONFIG_KVM_AMD_SEV=n. Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | Merge tag 'kvm-ppc-fixes-4.19-3' of ↵Paolo Bonzini2018-10-051-0/+10
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master Third set of PPC KVM fixes for 4.19 One patch here, fixing a potential host crash introduced (or at least exacerbated) by a previous fix for corruption relating to radix guest page faults and THP operations.
| * | KVM: PPC: Book3S HV: Avoid crash from THP collapse during radix page faultPaul Mackerras2018-10-041-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 71d29f43b633 ("KVM: PPC: Book3S HV: Don't use compound_order to determine host mapping size", 2018-09-11) added a call to __find_linux_pte() and a dereference of the returned PTE pointer to the radix page fault path in the common case where the page is normal system memory. Previously, __find_linux_pte() was only called for mappings to physical addresses which don't have a page struct (e.g. memory-mapped I/O) or where the page struct is marked as reserved memory. This exposes us to the possibility that the returned PTE pointer could be NULL, for example in the case of a concurrent THP collapse operation. Dereferencing the returned NULL pointer causes a host crash. To fix this, we check for NULL, and if it is NULL, we retry the operation by returning to the guest, with the expectation that it will generate the same page fault again (unless of course it has been fixed up by another CPU in the meantime). Fixes: 71d29f43b633 ("KVM: PPC: Book3S HV: Don't use compound_order to determine host mapping size") Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
* | | kvm: nVMX: fix entry with pending interrupt if APICv is enabledPaolo Bonzini2018-10-041-12/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit b5861e5cf2fcf83031ea3e26b0a69d887adf7d21 introduced a check on the interrupt-window and NMI-window CPU execution controls in order to inject an external interrupt vmexit before the first guest instruction executes. However, when APIC virtualization is enabled the host does not need a vmexit in order to inject an interrupt at the next interrupt window; instead, it just places the interrupt vector in RVI and the processor will inject it as soon as possible. Therefore, on machines with APICv it is not enough to check the CPU execution controls: the same scenario can also happen if RVI>vPPR. Fixes: b5861e5cf2fcf83031ea3e26b0a69d887adf7d21 Reviewed-by: Nikita Leshchenko <nikita.leshchenko@oracle.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Liran Alon <liran.alon@oracle.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: VMX: hide flexpriority from guest when disabled at the module levelPaolo Bonzini2018-10-041-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As of commit 8d860bbeedef ("kvm: vmx: Basic APIC virtualization controls have three settings"), KVM will disable VIRTUALIZE_APIC_ACCESSES when a nested guest writes APIC_BASE MSR and kvm-intel.flexpriority=0, whereas previously KVM would allow a nested guest to enable VIRTUALIZE_APIC_ACCESSES so long as it's supported in hardware. That is, KVM now advertises VIRTUALIZE_APIC_ACCESSES to a guest but doesn't (always) allow setting it when kvm-intel.flexpriority=0, and may even initially allow the control and then clear it when the nested guest writes APIC_BASE MSR, which is decidedly odd even if it doesn't cause functional issues. Hide the control completely when the module parameter is cleared. reported-by: Sean Christopherson <sean.j.christopherson@intel.com> Fixes: 8d860bbeedef ("kvm: vmx: Basic APIC virtualization controls have three settings") Cc: Jim Mattson <jmattson@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: VMX: check for existence of secondary exec controls before accessingSean Christopherson2018-10-041-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Return early from vmx_set_virtual_apic_mode() if the processor doesn't support VIRTUALIZE_APIC_ACCESSES or VIRTUALIZE_X2APIC_MODE, both of which reside in SECONDARY_VM_EXEC_CONTROL. This eliminates warnings due to VMWRITEs to SECONDARY_VM_EXEC_CONTROL (VMCS field 401e) failing on processors without secondary exec controls. Remove the similar check for TPR shadowing as it is incorporated in the flexpriority_enabled check and the APIC-related code in vmx_update_msr_bitmap() is further gated by VIRTUALIZE_X2APIC_MODE. Reported-by: Gerhard Wiesinger <redhat@wiesinger.com> Fixes: 8d860bbeedef ("kvm: vmx: Basic APIC virtualization controls have three settings") Cc: Jim Mattson <jmattson@google.com> Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: x86: fix L1TF's MMIO GFN calculationSean Christopherson2018-10-011-4/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One defense against L1TF in KVM is to always set the upper five bits of the *legal* physical address in the SPTEs for non-present and reserved SPTEs, e.g. MMIO SPTEs. In the MMIO case, the GFN of the MMIO SPTE may overlap with the upper five bits that are being usurped to defend against L1TF. To preserve the GFN, the bits of the GFN that overlap with the repurposed bits are shifted left into the reserved bits, i.e. the GFN in the SPTE will be split into high and low parts. When retrieving the GFN from the MMIO SPTE, e.g. to check for an MMIO access, get_mmio_spte_gfn() unshifts the affected bits and restores the original GFN for comparison. Unfortunately, get_mmio_spte_gfn() neglects to mask off the reserved bits in the SPTE that were used to store the upper chunk of the GFN. As a result, KVM fails to detect MMIO accesses whose GPA overlaps the repurprosed bits, which in turn causes guest panics and hangs. Fix the bug by generating a mask that covers the lower chunk of the GFN, i.e. the bits that aren't shifted by the L1TF mitigation. The alternative approach would be to explicitly zero the five reserved bits that are used to store the upper chunk of the GFN, but that requires additional run-time computation and makes an already-ugly bit of code even more inscrutable. I considered adding a WARN_ON_ONCE(low_phys_bits-1 <= PAGE_SHIFT) to warn if GENMASK_ULL() generated a nonsensical value, but that seemed silly since that would mean a system that supports VMX has less than 18 bits of physical address space... Reported-by: Sakari Ailus <sakari.ailus@iki.fi> Fixes: d9b47449c1a1 ("kvm: x86: Set highest physical address bits in non-present/reserved SPTEs") Cc: Junaid Shahid <junaids@google.com> Cc: Jim Mattson <jmattson@google.com> Cc: stable@vger.kernel.org Reviewed-by: Junaid Shahid <junaids@google.com> Tested-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | tools/kvm_stat: cut down decimal places in update interval dialogStefan Raspl2018-10-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | We currently display the default number of decimal places for floats in _show_set_update_interval(), which is quite pointless. Cutting down to a single decimal place. Signed-off-by: Stefan Raspl <raspl@linux.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: nVMX: Fix emulation of VM_ENTRY_LOAD_BNDCFGSLiran Alon2018-10-011-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | L2 IA32_BNDCFGS should be updated with vmcs12->guest_bndcfgs only when VM_ENTRY_LOAD_BNDCFGS is specified in vmcs12->vm_entry_controls. Otherwise, L2 IA32_BNDCFGS should be set to vmcs01->guest_bndcfgs which is L1 IA32_BNDCFGS. Reviewed-by: Nikita Leshchenko <nikita.leshchenko@oracle.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: x86: Do not use kvm_x86_ops->mpx_supported() directlyLiran Alon2018-10-012-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a87036add092 ("KVM: x86: disable MPX if host did not enable MPX XSAVE features") introduced kvm_mpx_supported() to return true iff MPX is enabled in the host. However, that commit seems to have missed replacing some calls to kvm_x86_ops->mpx_supported() to kvm_mpx_supported(). Complete original commit by replacing remaining calls to kvm_mpx_supported(). Fixes: a87036add092 ("KVM: x86: disable MPX if host did not enable MPX XSAVE features") Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: nVMX: Do not expose MPX VMX controls when guest MPX disabledLiran Alon2018-10-011-6/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before this commit, KVM exposes MPX VMX controls to L1 guest only based on if KVM and host processor supports MPX virtualization. However, these controls should be exposed to guest only in case guest vCPU supports MPX. Without this change, a L1 guest running with kernel which don't have commit 691bd4340bef ("kvm: vmx: allow host to access guest MSR_IA32_BNDCFGS") asserts in QEMU on the following: qemu-kvm: error: failed to set MSR 0xd90 to 0x0 qemu-kvm: .../qemu-2.10.0/target/i386/kvm.c:1801 kvm_put_msrs: Assertion 'ret == cpu->kvm_msr_buf->nmsrs failed' This is because L1 KVM kvm_init_msr_list() will see that vmx_mpx_supported() (As it only checks MPX VMX controls support) and therefore KVM_GET_MSR_INDEX_LIST IOCTL will include MSR_IA32_BNDCFGS. However, later when L1 will attempt to set this MSR via KVM_SET_MSRS IOCTL, it will fail because !guest_cpuid_has_mpx(vcpu). Therefore, fix the issue by exposing MPX VMX controls to L1 guest only when vCPU supports MPX. Fixes: 36be0b9deb23 ("KVM: x86: Add nested virtualization support for MPX") Reported-by: Eyal Moscovici <eyal.moscovici@oracle.com> Reviewed-by: Nikita Leshchenko <nikita.leshchenko@oracle.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | KVM: x86: never trap MSR_KERNEL_GS_BASEPaolo Bonzini2018-09-241-37/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KVM has an old optimization whereby accesses to the kernel GS base MSR are trapped when the guest is in 32-bit and not when it is in 64-bit mode. The idea is that swapgs is not available in 32-bit mode, thus the guest has no reason to access the MSR unless in 64-bit mode and 32-bit applications need not pay the price of switching the kernel GS base between the host and the guest values. However, this optimization adds complexity to the code for little benefit (these days most guests are going to be 64-bit anyway) and in fact broke after commit 678e315e78a7 ("KVM: vmx: add dedicated utility to access guest's kernel_gs_base", 2018-08-06); the guest kernel GS base can be corrupted across SMIs and UEFI Secure Boot is therefore broken (a secure boot Linux guest, for example, fails to reach the login prompt about half the time). This patch just removes the optimization; the kernel GS base MSR is now never trapped by KVM, similarly to the FS and GS base MSRs. Fixes: 678e315e78a780dbef384b92339c8414309dbc11 Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmGreg Kroah-Hartman2018-09-2127-244/+537
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Paolo writes: "It's mostly small bugfixes and cleanups, mostly around x86 nested virtualization. One important change, not related to nested virtualization, is that the ability for the guest kernel to trap CPUID instructions (in Linux that's the ARCH_SET_CPUID arch_prctl) is now masked by default. This is because the feature is detected through an MSR; a very bad idea that Intel seems to like more and more. Some applications choke if the other fields of that MSR are not initialized as on real hardware, hence we have to disable the whole MSR by default, as was the case before Linux 4.12." * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (23 commits) KVM: nVMX: Fix bad cleanup on error of get/set nested state IOCTLs kvm: selftests: Add platform_info_test KVM: x86: Control guest reads of MSR_PLATFORM_INFO KVM: x86: Turbo bits in MSR_PLATFORM_INFO nVMX x86: Check VPID value on vmentry of L2 guests nVMX x86: check posted-interrupt descriptor addresss on vmentry of L2 KVM: nVMX: Wake blocked vCPU in guest-mode if pending interrupt in virtual APICv KVM: VMX: check nested state and CR4.VMXE against SMM kvm: x86: make kvm_{load|put}_guest_fpu() static x86/hyper-v: rename ipi_arg_{ex,non_ex} structures KVM: VMX: use preemption timer to force immediate VMExit KVM: VMX: modify preemption timer bit only when arming timer KVM: VMX: immediately mark preemption timer expired only for zero value KVM: SVM: Switch to bitmap_zalloc() KVM/MMU: Fix comment in walk_shadow_page_lockless_end() kvm: selftests: use -pthread instead of -lpthread KVM: x86: don't reset root in kvm_mmu_setup() kvm: mmu: Don't read PDPTEs when paging is not enabled x86/kvm/lapic: always disable MMIO interface in x2APIC mode KVM: s390: Make huge pages unavailable in ucontrol VMs ...
| * | | KVM: nVMX: Fix bad cleanup on error of get/set nested state IOCTLsLiran Alon2018-09-201-8/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The handlers of IOCTLs in kvm_arch_vcpu_ioctl() are expected to set their return value in "r" local var and break out of switch block when they encounter some error. This is because vcpu_load() is called before the switch block which have a proper cleanup of vcpu_put() afterwards. However, KVM_{GET,SET}_NESTED_STATE IOCTLs handlers just return immediately on error without performing above mentioned cleanup. Thus, change these handlers to behave as expected. Fixes: 8fcc4b5923af ("kvm: nVMX: Introduce KVM_CAP_NESTED_STATE") Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Reviewed-by: Patrick Colp <patrick.colp@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | kvm: selftests: Add platform_info_testDrew Schmitt2018-09-205-1/+206
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Test guest access to MSR_PLATFORM_INFO when the capability is enabled or disabled. Signed-off-by: Drew Schmitt <dasch@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | KVM: x86: Control guest reads of MSR_PLATFORM_INFODrew Schmitt2018-09-204-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add KVM_CAP_MSR_PLATFORM_INFO so that userspace can disable guest access to reads of MSR_PLATFORM_INFO. Disabling access to reads of this MSR gives userspace the control to "expose" this platform-dependent information to guests in a clear way. As it exists today, guests that read this MSR would get unpopulated information if userspace hadn't already set it (and prior to this patch series, only the CPUID faulting information could have been populated). This existing interface could be confusing if guests don't handle the potential for incorrect/incomplete information gracefully (e.g. zero reported for base frequency). Signed-off-by: Drew Schmitt <dasch@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | KVM: x86: Turbo bits in MSR_PLATFORM_INFODrew Schmitt2018-09-201-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow userspace to set turbo bits in MSR_PLATFORM_INFO. Previously, only the CPUID faulting bit was settable. But now any bit in MSR_PLATFORM_INFO would be settable. This can be used, for example, to convey frequency information about the platform on which the guest is running. Signed-off-by: Drew Schmitt <dasch@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | nVMX x86: Check VPID value on vmentry of L2 guestsKrish Sadhukhan2018-09-201-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | According to section "Checks on VMX Controls" in Intel SDM vol 3C, the following check needs to be enforced on vmentry of L2 guests: If the 'enable VPID' VM-execution control is 1, the value of the of the VPID VM-execution control field must not be 0000H. Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | nVMX x86: check posted-interrupt descriptor addresss on vmentry of L2Krish Sadhukhan2018-09-201-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | According to section "Checks on VMX Controls" in Intel SDM vol 3C, the following check needs to be enforced on vmentry of L2 guests: - Bits 5:0 of the posted-interrupt descriptor address are all 0. - The posted-interrupt descriptor address does not set any bits beyond the processor's physical-address width. Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Karl Heubaum <karl.heubaum@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | KVM: nVMX: Wake blocked vCPU in guest-mode if pending interrupt in virtual APICvLiran Alon2018-09-203-1/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case L1 do not intercept L2 HLT or enter L2 in HLT activity-state, it is possible for a vCPU to be blocked while it is in guest-mode. According to Intel SDM 26.6.5 Interrupt-Window Exiting and Virtual-Interrupt Delivery: "These events wake the logical processor if it just entered the HLT state because of a VM entry". Therefore, if L1 enters L2 in HLT activity-state and L2 has a pending deliverable interrupt in vmcs12->guest_intr_status.RVI, then the vCPU should be waken from the HLT state and injected with the interrupt. In addition, if while the vCPU is blocked (while it is in guest-mode), it receives a nested posted-interrupt, then the vCPU should also be waken and injected with the posted interrupt. To handle these cases, this patch enhances kvm_vcpu_has_events() to also check if there is a pending interrupt in L2 virtual APICv provided by L1. That is, it evaluates if there is a pending virtual interrupt for L2 by checking RVI[7:4] > VPPR[7:4] as specified in Intel SDM 29.2.1 Evaluation of Pending Interrupts. Note that this also handles the case of nested posted-interrupt by the fact RVI is updated in vmx_complete_nested_posted_interrupt() which is called from kvm_vcpu_check_block() -> kvm_arch_vcpu_runnable() -> kvm_vcpu_running() -> vmx_check_nested_events() -> vmx_complete_nested_posted_interrupt(). Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | KVM: VMX: check nested state and CR4.VMXE against SMMPaolo Bonzini2018-09-201-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | VMX cannot be enabled under SMM, check it when CR4 is set and when nested virtualization state is restored. This should fix some WARNs reported by syzkaller, mostly around alloc_shadow_vmcs. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | kvm: x86: make kvm_{load|put}_guest_fpu() staticSebastian Andrzej Siewior2018-09-202-25/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The functions kvm_load_guest_fpu() kvm_put_guest_fpu() are only used locally, make them static. This requires also that both functions are moved because they are used before their implementation. Those functions were exported (via EXPORT_SYMBOL) before commit e5bb40251a920 ("KVM: Drop kvm_{load,put}_guest_fpu() exports"). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | x86/hyper-v: rename ipi_arg_{ex,non_ex} structuresVitaly Kuznetsov2018-09-202-11/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These structures are going to be used from KVM code so let's make their names reflect their Hyper-V origin. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Acked-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | KVM: VMX: use preemption timer to force immediate VMExitSean Christopherson2018-09-204-2/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A VMX preemption timer value of '0' is guaranteed to cause a VMExit prior to the CPU executing any instructions in the guest. Use the preemption timer (if it's supported) to trigger immediate VMExit in place of the current method of sending a self-IPI. This ensures that pending VMExit injection to L1 occurs prior to executing any instructions in the guest (regardless of nesting level). When deferring VMExit injection, KVM generates an immediate VMExit from the (possibly nested) guest by sending itself an IPI. Because hardware interrupts are blocked prior to VMEnter and are unblocked (in hardware) after VMEnter, this results in taking a VMExit(INTR) before any guest instruction is executed. But, as this approach relies on the IPI being received before VMEnter executes, it only works as intended when KVM is running as L0. Because there are no architectural guarantees regarding when IPIs are delivered, when running nested the INTR may "arrive" long after L2 is running e.g. L0 KVM doesn't force an immediate switch to L1 to deliver an INTR. For the most part, this unintended delay is not an issue since the events being injected to L1 also do not have architectural guarantees regarding their timing. The notable exception is the VMX preemption timer[1], which is architecturally guaranteed to cause a VMExit prior to executing any instructions in the guest if the timer value is '0' at VMEnter. Specifically, the delay in injecting the VMExit causes the preemption timer KVM unit test to fail when run in a nested guest. Note: this approach is viable even on CPUs with a broken preemption timer, as broken in this context only means the timer counts at the wrong rate. There are no known errata affecting timer value of '0'. [1] I/O SMIs also have guarantees on when they arrive, but I have no idea if/how those are emulated in KVM. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> [Use a hook for SVM instead of leaving the default in x86.c - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | KVM: VMX: modify preemption timer bit only when arming timerSean Christopherson2018-09-201-29/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a singular location where the VMX preemption timer bit is set/cleared so that future usages of the preemption timer can ensure the VMCS bit is up-to-date without having to modify unrelated code paths. For example, the preemption timer can be used to force an immediate VMExit. Cache the status of the timer to avoid redundant VMREAD and VMWRITE, e.g. if the timer stays armed across multiple VMEnters/VMExits. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | KVM: VMX: immediately mark preemption timer expired only for zero valueSean Christopherson2018-09-201-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A VMX preemption timer value of '0' at the time of VMEnter is architecturally guaranteed to cause a VMExit prior to the CPU executing any instructions in the guest. This architectural definition is in place to ensure that a previously expired timer is correctly recognized by the CPU as it is possible for the timer to reach zero and not trigger a VMexit due to a higher priority VMExit being signalled instead, e.g. a pending #DB that morphs into a VMExit. Whether by design or coincidence, commit f4124500c2c1 ("KVM: nVMX: Fully emulate preemption timer") special cased timer values of '0' and '1' to ensure prompt delivery of the VMExit. Unlike '0', a timer value of '1' has no has no architectural guarantees regarding when it is delivered. Modify the timer emulation to trigger immediate VMExit if and only if the timer value is '0', and document precisely why '0' is special. Do this even if calibration of the virtual TSC failed, i.e. VMExit will occur immediately regardless of the frequency of the timer. Making only '0' a special case gives KVM leeway to be more aggressive in ensuring the VMExit is injected prior to executing instructions in the nested guest, and also eliminates any ambiguity as to why '1' is a special case, e.g. why wasn't the threshold for a "short timeout" set to 10, 100, 1000, etc... Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | KVM: SVM: Switch to bitmap_zalloc()Andy Shevchenko2018-09-201-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch to bitmap_zalloc() to show clearly what we are allocating. Besides that it returns pointer of bitmap type instead of opaque void *. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | KVM/MMU: Fix comment in walk_shadow_page_lockless_end()Tianyu Lan2018-09-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kvm_commit_zap_page() has been renamed to kvm_mmu_commit_zap_page() This patch is to fix the commit. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | kvm: selftests: use -pthread instead of -lpthreadLei Yang2018-09-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I run into the following error testing/selftests/kvm/dirty_log_test.c:285: undefined reference to `pthread_create' testing/selftests/kvm/dirty_log_test.c:297: undefined reference to `pthread_join' collect2: error: ld returned 1 exit status my gcc version is gcc version 4.8.4 "-pthread" would work everywhere Signed-off-by: Lei Yang <Lei.Yang@windriver.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | KVM: x86: don't reset root in kvm_mmu_setup()Wei Yang2018-09-201-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Here is the code path which shows kvm_mmu_setup() is invoked after kvm_mmu_create(). Since kvm_mmu_setup() is only invoked in this code path, this means the root_hpa and prev_roots are guaranteed to be invalid. And it is not necessary to reset it again. kvm_vm_ioctl_create_vcpu() kvm_arch_vcpu_create() vmx_create_vcpu() kvm_vcpu_init() kvm_arch_vcpu_init() kvm_mmu_create() kvm_arch_vcpu_setup() kvm_mmu_setup() kvm_init_mmu() This patch set reset_roots to false in kmv_mmu_setup(). Fixes: 50c28f21d045dde8c52548f8482d456b3f0956f5 Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | kvm: mmu: Don't read PDPTEs when paging is not enabledJunaid Shahid2018-09-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kvm should not attempt to read guest PDPTEs when CR0.PG = 0 and CR4.PAE = 1. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | x86/kvm/lapic: always disable MMIO interface in x2APIC modeVitaly Kuznetsov2018-09-202-3/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When VMX is used with flexpriority disabled (because of no support or if disabled with module parameter) MMIO interface to lAPIC is still available in x2APIC mode while it shouldn't be (kvm-unit-tests): PASS: apic_disable: Local apic enabled in x2APIC mode PASS: apic_disable: CPUID.1H:EDX.APIC[bit 9] is set FAIL: apic_disable: *0xfee00030: 50014 The issue appears because we basically do nothing while switching to x2APIC mode when APIC access page is not used. apic_mmio_{read,write} only check if lAPIC is disabled before proceeding to actual write. When APIC access is virtualized we correctly manipulate with VMX controls in vmx_set_virtual_apic_mode() and we don't get vmexits from memory writes in x2APIC mode so there's no issue. Disabling MMIO interface seems to be easy. The question is: what do we do with these reads and writes? If we add apic_x2apic_mode() check to apic_mmio_in_range() and return -EOPNOTSUPP these reads and writes will go to userspace. When lAPIC is in kernel, Qemu uses this interface to inject MSIs only (see kvm_apic_mem_write() in hw/i386/kvm/apic.c). This somehow works with disabled lAPIC but when we're in xAPIC mode we will get a real injected MSI from every write to lAPIC. Not good. The simplest solution seems to be to just ignore writes to the region and return ~0 for all reads when we're in x2APIC mode. This is what this patch does. However, this approach is inconsistent with what currently happens when flexpriority is enabled: we allocate APIC access page and create KVM memory region so in x2APIC modes all reads and writes go to this pre-allocated page which is, btw, the same for all vCPUs. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | Merge tag 'kvm-ppc-fixes-4.19-2' of ↵Paolo Bonzini2018-09-188-143/+99
| |\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD Second set of PPC KVM fixes for 4.19 Two fixes for KVM on POWER machines. Both of these relate to memory corruption and host crashes seen when transparent huge pages are enabled. The first fixes a host crash that can occur when a DMA mapping is removed by the guest and the page mapped was part of a transparent huge page; the second fixes corruption that could occur when a hypervisor page fault for a radix guest is being serviced at the same time that the backing page is being collapsed or split.
| | * | KVM: PPC: Book3S HV: Don't use compound_order to determine host mapping sizeNicholas Piggin2018-09-121-54/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | THP paths can defer splitting compound pages until after the actual remap and TLB flushes to split a huge PMD/PUD. This causes radix partition scope page table mappings to get out of synch with the host qemu page table mappings. This results in random memory corruption in the guest when running with THP. The easiest way to reproduce is use KVM balloon to free up a lot of memory in the guest and then shrink the balloon to give the memory back, while some work is being done in the guest. Cc: David Gibson <david@gibson.dropbear.id.au> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: kvm-ppc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
| | * | KVM: PPC: Avoid marking DMA-mapped pages dirty in real modeAlexey Kardashevskiy2018-09-127-89/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At the moment the real mode handler of H_PUT_TCE calls iommu_tce_xchg_rm() which in turn reads the old TCE and if it was a valid entry, marks the physical page dirty if it was mapped for writing. Since it is in real mode, realmode_pfn_to_page() is used instead of pfn_to_page() to get the page struct. However SetPageDirty() itself reads the compound page head and returns a virtual address for the head page struct and setting dirty bit for that kills the system. This adds additional dirty bit tracking into the MM/IOMMU API for use in the real mode. Note that this does not change how VFIO and KVM (in virtual mode) set this bit. The KVM (real mode) changes include: - use the lowest bit of the cached host phys address to carry the dirty bit; - mark pages dirty when they are unpinned which happens when the preregistered memory is released which always happens in virtual mode; - add mm_iommu_ua_mark_dirty_rm() helper to set delayed dirty bit; - change iommu_tce_xchg_rm() to take the kvm struct for the mm to use in the new mm_iommu_ua_mark_dirty_rm() helper; - move iommu_tce_xchg_rm() to book3s_64_vio_hv.c (which is the only caller anyway) to reduce the real mode KVM and IOMMU knowledge across different subsystems. This removes realmode_pfn_to_page() as it is not used anymore. While we at it, remove some EXPORT_SYMBOL_GPL() as that code is for the real mode only and modules cannot call it anyway. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
| * | | Merge tag 'kvm-s390-master-4.19-2' of ↵Paolo Bonzini2018-09-183-4/+7
| |\ \ \ | | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Fixes for 4.19 - more fallout from the hugetlbfs enablement - bugfix for vma handling
| | * | KVM: s390: Make huge pages unavailable in ucontrol VMsJanosch Frank2018-09-122-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We currently do not notify all gmaps when using gmap_pmdp_xchg(), due to locking constraints. This makes ucontrol VMs, which is the only VM type that creates multiple gmaps, incompatible with huge pages. Also we would need to hold the guest_table_lock of all gmaps that have this vmaddr maped to synchronize access to the pmd. ucontrol VMs are rather exotic and creating a new locking concept is no easy task. Hence we return EINVAL when trying to active KVM_CAP_S390_HPAGE_1M and report it as being not available when checking for it. Fixes: a4499382 ("KVM: s390: Add huge page enablement control") Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-Id: <20180801112508.138159-1-frankja@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
| | * | s390/mm: Check for valid vma before zapping in gmap_discardJanosch Frank2018-09-121-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Userspace could have munmapped the area before doing unmapping from the gmap. This would leave us with a valid vmaddr, but an invalid vma from which we would try to zap memory. Let's check before using the vma. Fixes: 1e133ab296f3 ("s390/mm: split arch/s390/mm/pgtable.c") Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Message-Id: <20180816082432.78828-1-frankja@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
* | | | Merge tag 'upstream-4.19-rc4' of git://git.infradead.org/linux-ubifsGreg Kroah-Hartman2018-09-212-25/+6
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Richard writes: "This pull request contains fixes for UBIFS: - A wrong UBIFS assertion in mount code - Fix for a NULL pointer deref in mount code - Revert of a bad fix for xattrs" * tag 'upstream-4.19-rc4' of git://git.infradead.org/linux-ubifs: Revert "ubifs: xattr: Don't operate on deleted inodes" ubifs: drop false positive assertion ubifs: Check for name being NULL while mounting
| * | | | Revert "ubifs: xattr: Don't operate on deleted inodes"Richard Weinberger2018-09-201-24/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 11a6fc3dc743e22fb50f2196ec55bee5140d3c52. UBIFS wants to assert that xattr operations are only issued on files with positive link count. The said patch made this operations return -ENOENT for unlinked files such that the asserts will no longer trigger. This was wrong since xattr operations are perfectly fine on unlinked files. Instead the assertions need to be fixed/removed. Cc: <stable@vger.kernel.org> Fixes: 11a6fc3dc743 ("ubifs: xattr: Don't operate on deleted inodes") Reported-by: Koen Vandeputte <koen.vandeputte@ncentric.com> Tested-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | | ubifs: drop false positive assertionSascha Hauer2018-09-201-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following sequence triggers ubifs_assert(c, c->lst.taken_empty_lebs > 0); at the end of ubifs_remount_fs(): mount -t ubifs /dev/ubi0_0 /mnt echo 1 > /sys/kernel/debug/ubifs/ubi0_0/ro_error umount /mnt mount -t ubifs -o ro /dev/ubix_y /mnt mount -o remount,ro /mnt The resulting UBIFS assert failed in ubifs_remount_fs at 1878 (pid 161) is a false positive. In the case above c->lst.taken_empty_lebs has never been changed from its initial zero value. This will only happen when the deferred recovery is done. Fix this by doing the assertion only when recovery has been done already. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | | ubifs: Check for name being NULL while mountingRichard Weinberger2018-09-201-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The requested device name can be NULL or an empty string. Check for that and refuse to continue. UBIFS has to do this manually since we cannot use mount_bdev(), which checks for this condition. Fixes: 1e51764a3c2ac ("UBIFS: add new flash file system") Reported-by: syzbot+38bd0f7865e5c6379280@syzkaller.appspotmail.com Signed-off-by: Richard Weinberger <richard@nod.at>
* | | | | Merge tag 'for-linus-20180920' of git://git.kernel.dk/linux-blockGreg Kroah-Hartman2018-09-213-2/+19
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jens writes: "Storage fixes for 4.19-rc5 - Fix for leaking kernel pointer in floppy ioctl (Andy Whitcroft) - NVMe pull request from Christoph, and a single ANA log page fix (Hannes) - Regression fix for libata qd32 support, where we trigger an illegal active command transition. This fixes a CD-ROM detection issue that was reported, but could also trigger premature completion of the internal tag (me)" * tag 'for-linus-20180920' of git://git.kernel.dk/linux-block: floppy: Do not copy a kernel pointer to user memory in FDGETPRM ioctl libata: mask swap internal and hardware tag nvme: count all ANA groups for ANA Log page
| * \ \ \ \ Merge branch 'nvme-4.19' of git://git.infradead.org/nvme into for-linusJens Axboe2018-09-201-0/+4
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull NVMe fix from Christoph. * 'nvme-4.19' of git://git.infradead.org/nvme: nvme: count all ANA groups for ANA Log page
| | * | | | | nvme: count all ANA groups for ANA Log pageHannes Reinecke2018-09-171-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When issuing a short read on the ANA log page the number of groups should not change, even though the final returned data might contain less groups than that number. Signed-off-by: Hannes Reinecke <hare@suse.com> [switched to a for loop] Signed-off-by: Christoph Hellwig <hch@lst.de>
| * | | | | | floppy: Do not copy a kernel pointer to user memory in FDGETPRM ioctlAndy Whitcroft2018-09-201-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The final field of a floppy_struct is the field "name", which is a pointer to a string in kernel memory. The kernel pointer should not be copied to user memory. The FDGETPRM ioctl copies a floppy_struct to user memory, including this "name" field. This pointer cannot be used by the user and it will leak a kernel address to user-space, which will reveal the location of kernel code and data and undermine KASLR protection. Model this code after the compat ioctl which copies the returned data to a previously cleared temporary structure on the stack (excluding the name pointer) and copy out to userspace from there. As we already have an inparam union with an appropriate member and that memory is already cleared even for read only calls make use of that as a temporary store. Based on an initial patch by Brian Belleville. CVE-2018-7755 Signed-off-by: Andy Whitcroft <apw@canonical.com> Broke up long line. Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * | | | | | libata: mask swap internal and hardware tagJens Axboe2018-09-201-2/+12
| |/ / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | hen we're comparing the hardware completion mask passed in from the driver with the internal tag pending mask, we need to account for the fact that the internal tag is different from the hardware tag. If not, then we can end up either prematurely completing the internal tag (since it's not set in the hw mask), or simply flag an error: ata2: illegal qc_active transition (100000000->00000001) If the internal tag is set, then swap that with the hardware tag in this case before comparing with what the hardware reports. Fixes: 28361c403683 ("libata: add extra internal command") Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=201151 Cc: stable@vger.kernel.org Reported-by: Paul Sbarra <sbarra.paul@gmail.com> Tested-by: Paul Sbarra <sbarra.paul@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>