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* KVM: VMX: Fix rflags cache during vCPU resetWanpeng Li2018-02-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit c37c28730bb031cc8a44a130c2555c0f3efbe2d0 ] Reported by syzkaller: *** Guest State *** CR0: actual=0x0000000080010031, shadow=0x0000000060000010, gh_mask=fffffffffffffff7 CR4: actual=0x0000000000002061, shadow=0x0000000000000000, gh_mask=ffffffffffffe8f1 CR3 = 0x000000002081e000 RSP = 0x000000000000fffa RIP = 0x0000000000000000 RFLAGS=0x00023000 DR7 = 0x00000000000000 ^^^^^^^^^^ ------------[ cut here ]------------ WARNING: CPU: 6 PID: 24431 at /home/kernel/linux/arch/x86/kvm//x86.c:7302 kvm_arch_vcpu_ioctl_run+0x651/0x2ea0 [kvm] CPU: 6 PID: 24431 Comm: reprotest Tainted: G W OE 4.14.0+ #26 RIP: 0010:kvm_arch_vcpu_ioctl_run+0x651/0x2ea0 [kvm] RSP: 0018:ffff880291d179e0 EFLAGS: 00010202 Call Trace: kvm_vcpu_ioctl+0x479/0x880 [kvm] do_vfs_ioctl+0x142/0x9a0 SyS_ioctl+0x74/0x80 entry_SYSCALL_64_fastpath+0x23/0x9a The failed vmentry is triggered by the following beautified testcase: #include <unistd.h> #include <sys/syscall.h> #include <string.h> #include <stdint.h> #include <linux/kvm.h> #include <fcntl.h> #include <sys/ioctl.h> long r[5]; int main() { struct kvm_debugregs dr = { 0 }; r[2] = open("/dev/kvm", O_RDONLY); r[3] = ioctl(r[2], KVM_CREATE_VM, 0); r[4] = ioctl(r[3], KVM_CREATE_VCPU, 7); struct kvm_guest_debug debug = { .control = 0xf0403, .arch = { .debugreg[6] = 0x2, .debugreg[7] = 0x2 } }; ioctl(r[4], KVM_SET_GUEST_DEBUG, &debug); ioctl(r[4], KVM_RUN, 0); } which testcase tries to setup the processor specific debug registers and configure vCPU for handling guest debug events through KVM_SET_GUEST_DEBUG. The KVM_SET_GUEST_DEBUG ioctl will get and set rflags in order to set TF bit if single step is needed. All regs' caches are reset to avail and GUEST_RFLAGS vmcs field is reset to 0x2 during vCPU reset. However, the cache of rflags is not reset during vCPU reset. The function vmx_get_rflags() returns an unreset rflags cache value since the cache is marked avail, it is 0 after boot. Vmentry fails if the rflags reserved bit 1 is 0. This patch fixes it by resetting both the GUEST_RFLAGS vmcs field and its cache to 0x2 during vCPU reset. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: X86: Fix operand/address-size during instruction decodingWanpeng Li2018-02-071-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 3853be2603191829b442b64dac6ae8ba0c027bf9 ] Pedro reported: During tests that we conducted on KVM, we noticed that executing a "PUSH %ES" instruction under KVM produces different results on both memory and the SP register depending on whether EPT support is enabled. With EPT the SP is reduced by 4 bytes (and the written value is 0-padded) but without EPT support it is only reduced by 2 bytes. The difference can be observed when the CS.DB field is 1 (32-bit) but not when it's 0 (16-bit). The internal segment descriptor cache exist even in real/vm8096 mode. The CS.D also should be respected instead of just default operand/address-size/66H prefix/67H prefix during instruction decoding. This patch fixes it by also adjusting operand/address-size according to CS.D. Reported-by: Pedro Fonseca <pfonseca@cs.washington.edu> Tested-by: Pedro Fonseca <pfonseca@cs.washington.edu> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Pedro Fonseca <pfonseca@cs.washington.edu> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: Don't re-execute instruction when not passing CR2 valueLiran Alon2018-02-072-2/+3
| | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 9b8ae63798cb97e785a667ff27e43fa6220cb734 ] In case of instruction-decode failure or emulation failure, x86_emulate_instruction() will call reexecute_instruction() which will attempt to use the cr2 value passed to x86_emulate_instruction(). However, when x86_emulate_instruction() is called from emulate_instruction(), cr2 is not passed (passed as 0) and therefore it doesn't make sense to execute reexecute_instruction() logic at all. Fixes: 51d8b66199e9 ("KVM: cleanup emulate_instruction") Signed-off-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: emulator: Return to user-mode on L1 CPL=0 emulation failureLiran Alon2018-02-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 1f4dcb3b213235e642088709a1c54964d23365e9 ] On this case, handle_emulation_failure() fills kvm_run with internal-error information which it expects to be delivered to user-mode for further processing. However, the code reports a wrong return-value which makes KVM to never return to user-mode on this scenario. Fixes: 6d77dbfc88e3 ("KVM: inject #UD if instruction emulation fails and exit to userspace") Signed-off-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* um: Stop abusing __KERNEL__Richard Weinberger2018-02-071-3/+3
| | | | | | | | | | | | | | | commit 298e20ba8c197e8d429a6c8671550c41c7919033 upstream. Currently UML is abusing __KERNEL__ to distinguish between kernel and host code (os-Linux). It is better to use a custom define such that existing users of __KERNEL__ don't get confused. Signed-off-by: Richard Weinberger <richard@nod.at> Cc: Greg Hackmann <ghackmann@google.com> Cc: Bernie Innocenti <codewiz@google.com> Cc: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/microcode/intel: Extend BDW late-loading further with LLC size checkJia Zhang2018-01-311-2/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7e702d17ed138cf4ae7c00e8c00681ed464587c7 upstream. Commit b94b73733171 ("x86/microcode/intel: Extend BDW late-loading with a revision check") reduced the impact of erratum BDF90 for Broadwell model 79. The impact can be reduced further by checking the size of the last level cache portion per core. Tony: "The erratum says the problem only occurs on the large-cache SKUs. So we only need to avoid the update if we are on a big cache SKU that is also running old microcode." For more details, see erratum BDF90 in document #334165 (Intel Xeon Processor E7-8800/4800 v4 Product Family Specification Update) from September 2017. Fixes: b94b73733171 ("x86/microcode/intel: Extend BDW late-loading with a revision check") Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/1516321542-31161-1-git-send-email-zhang.jia@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/asm/32: Make sync_core() handle missing CPUID on all 32-bit kernelsAndy Lutomirski2018-01-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | commit 1c52d859cb2d417e7216d3e56bb7fea88444cec9 upstream. We support various non-Intel CPUs that don't have the CPUID instruction, so the M486 test was wrong. For now, fix it with a big hammer: handle missing CPUID on all 32-bit CPUs. Reported-by: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Juergen Gross <jgross@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Matthew Whitehead <tedheadster@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: xen-devel <Xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/685bd083a7c036f7769510b6846315b17d6ba71f.1481307769.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/microcode/intel: Extend BDW late-loading with a revision checkJia Zhang2018-01-171-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit b94b7373317164402ff7728d10f7023127a02b60 upstream. Instead of blacklisting all model 79 CPUs when attempting a late microcode loading, limit that only to CPUs with microcode revisions < 0x0b000021 because only on those late loading may cause a system hang. For such processors either: a) a BIOS update which might contain a newer microcode revision or b) the early microcode loading method should be considered. Processors with revisions 0x0b000021 or higher will not experience such hangs. For more details, see erratum BDF90 in document #334165 (Intel Xeon Processor E7-8800/4800 v4 Product Family Specification Update) from September 2017. [ bp: Heavily massage commit message and pr_* statements. ] Fixes: 723f2828a98c ("x86/microcode/intel: Disable late loading on model 79") Signed-off-by: Jia Zhang <qianyue.zj@alibaba-inc.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tony Luck <tony.luck@intel.com> Cc: x86-ml <x86@kernel.org> Link: http://lkml.kernel.org/r/1514772287-92959-1-git-send-email-qianyue.zj@alibaba-inc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/acpi: Reduce code duplication in mp_override_legacy_irq()Vikas C Sajjan2018-01-171-22/+5
| | | | | | | | | | | | | | | | | | | | | | commit 4ee2ec1b122599f7b10c849fa7915cebb37b7edb upstream. The new function mp_register_ioapic_irq() is a subset of the code in mp_override_legacy_irq(). Replace the code duplication by invoking mp_register_ioapic_irq() from mp_override_legacy_irq(). Signed-off-by: Vikas C Sajjan <vikas.cha.sajjan@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: linux-pm@vger.kernel.org Cc: kkamagui@gmail.com Cc: linux-acpi@vger.kernel.org Link: https://lkml.kernel.org/r/1510848825-21965-3-git-send-email-vikas.cha.sajjan@hpe.com Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/acpi: Handle SCI interrupts above legacy space gracefullyVikas C Sajjan2018-01-171-1/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 252714155f04c5d16989cb3aadb85fd1b5772f99 upstream. Platforms which support only IOAPIC mode, pass the SCI information above the legacy space (0-15) via the FADT mechanism and not via MADT. In such cases mp_override_legacy_irq() which is invoked from acpi_sci_ioapic_setup() to register SCI interrupts fails for interrupts greater equal 16, since it is meant to handle only the legacy space and emits error "Invalid bus_irq %u for legacy override". Add a new function to handle SCI interrupts >= 16 and invoke it conditionally in acpi_sci_ioapic_setup(). The code duplication due to this new function will be cleaned up in a separate patch. Co-developed-by: Sunil V L <sunil.vl@hpe.com> Signed-off-by: Vikas C Sajjan <vikas.cha.sajjan@hpe.com> Signed-off-by: Sunil V L <sunil.vl@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Abdul Lateef Attar <abdul-lateef.attar@hpe.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: linux-pm@vger.kernel.org Cc: kkamagui@gmail.com Cc: linux-acpi@vger.kernel.org Link: https://lkml.kernel.org/r/1510848825-21965-2-git-send-email-vikas.cha.sajjan@hpe.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kvm: vmx: Scrub hardware GPRs at VM-exitJim Mattson2018-01-172-1/+32
| | | | | | | | | | | | | | | | | | | | | commit 0cb5b30698fdc8f6b4646012e3acb4ddce430788 upstream. Guest GPR values are live in the hardware GPRs at VM-exit. Do not leave any guest values in hardware GPRs after the guest GPR values are saved to the vcpu_vmx structure. This is a partial mitigation for CVE 2017-5715 and CVE 2017-5753. Specifically, it defeats the Project Zero PoC for CVE 2017-5715. Suggested-by: Eric Northup <digitaleric@google.com> Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Eric Northup <digitaleric@google.com> Reviewed-by: Benjamin Serebrin <serebrin@google.com> Reviewed-by: Andrew Honig <ahonig@google.com> [Paolo: Add AMD bits, Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: X86: Fix load RFLAGS w/o the fixed bitWanpeng Li2018-01-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d73235d17ba63b53dc0e1051dbc10a1f1be91b71 upstream. *** Guest State *** CR0: actual=0x0000000000000030, shadow=0x0000000060000010, gh_mask=fffffffffffffff7 CR4: actual=0x0000000000002050, shadow=0x0000000000000000, gh_mask=ffffffffffffe871 CR3 = 0x00000000fffbc000 RSP = 0x0000000000000000 RIP = 0x0000000000000000 RFLAGS=0x00000000 DR7 = 0x0000000000000400 ^^^^^^^^^^ The failed vmentry is triggered by the following testcase when ept=Y: #include <unistd.h> #include <sys/syscall.h> #include <string.h> #include <stdint.h> #include <linux/kvm.h> #include <fcntl.h> #include <sys/ioctl.h> long r[5]; int main() { r[2] = open("/dev/kvm", O_RDONLY); r[3] = ioctl(r[2], KVM_CREATE_VM, 0); r[4] = ioctl(r[3], KVM_CREATE_VCPU, 7); struct kvm_regs regs = { .rflags = 0, }; ioctl(r[4], KVM_SET_REGS, &regs); ioctl(r[4], KVM_RUN, 0); } X86 RFLAGS bit 1 is fixed set, userspace can simply clearing bit 1 of RFLAGS with KVM_SET_REGS ioctl which results in vmentry fails. This patch fixes it by oring X86_EFLAGS_FIXED during ioctl. Suggested-by: Jim Mattson <jmattson@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Quan Xu <quan.xu0@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Jim Mattson <jmattson@google.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: correct async page present tracepointWanpeng Li2017-12-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 24dccf83a121b8a4ad5c2ad383a8184ef6c266ee ] After async pf setup successfully, there is a broadcast wakeup w/ special token 0xffffffff which tells vCPU that it should wake up all processes waiting for APFs though there is no real process waiting at the moment. The async page present tracepoint print prematurely and fails to catch the special token setup. This patch fixes it by moving the async page present tracepoint after the special token setup. Before patch: qemu-system-x86-8499 [006] ...1 5973.473292: kvm_async_pf_ready: token 0x0 gva 0x0 After patch: qemu-system-x86-8499 [006] ...1 5973.473292: kvm_async_pf_ready: token 0xffffffff gva 0x0 Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* crypto: salsa20 - fix blkcipher_walk API usageEric Biggers2017-12-201-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit ecaaab5649781c5a0effdaf298a925063020500e upstream. When asked to encrypt or decrypt 0 bytes, both the generic and x86 implementations of Salsa20 crash in blkcipher_walk_done(), either when doing 'kfree(walk->buffer)' or 'free_page((unsigned long)walk->page)', because walk->buffer and walk->page have not been initialized. The bug is that Salsa20 is calling blkcipher_walk_done() even when nothing is in 'walk.nbytes'. But blkcipher_walk_done() is only meant to be called when a nonzero number of bytes have been provided. The broken code is part of an optimization that tries to make only one call to salsa20_encrypt_bytes() to process inputs that are not evenly divisible by 64 bytes. To fix the bug, just remove this "optimization" and use the blkcipher_walk API the same way all the other users do. Reproducer: #include <linux/if_alg.h> #include <sys/socket.h> #include <unistd.h> int main() { int algfd, reqfd; struct sockaddr_alg addr = { .salg_type = "skcipher", .salg_name = "salsa20", }; char key[16] = { 0 }; algfd = socket(AF_ALG, SOCK_SEQPACKET, 0); bind(algfd, (void *)&addr, sizeof(addr)); reqfd = accept(algfd, 0, 0); setsockopt(algfd, SOL_ALG, ALG_SET_KEY, key, sizeof(key)); read(reqfd, key, sizeof(key)); } Reported-by: syzbot <syzkaller@googlegroups.com> Fixes: eb6f13eb9f81 ("[CRYPTO] salsa20_generic: Fix multi-page processing") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: nVMX: reset nested_run_pending if the vCPU is going to be resetWanpeng Li2017-12-161-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 2f707d97982286b307ef2a9b034e19aabc1abb56 ] Reported by syzkaller: WARNING: CPU: 1 PID: 27742 at arch/x86/kvm/vmx.c:11029 nested_vmx_vmexit+0x5c35/0x74d0 arch/x86/kvm/vmx.c:11029 CPU: 1 PID: 27742 Comm: a.out Not tainted 4.10.0+ #229 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:15 [inline] dump_stack+0x2ee/0x3ef lib/dump_stack.c:51 panic+0x1fb/0x412 kernel/panic.c:179 __warn+0x1c4/0x1e0 kernel/panic.c:540 warn_slowpath_null+0x2c/0x40 kernel/panic.c:583 nested_vmx_vmexit+0x5c35/0x74d0 arch/x86/kvm/vmx.c:11029 vmx_leave_nested arch/x86/kvm/vmx.c:11136 [inline] vmx_set_msr+0x1565/0x1910 arch/x86/kvm/vmx.c:3324 kvm_set_msr+0xd4/0x170 arch/x86/kvm/x86.c:1099 do_set_msr+0x11e/0x190 arch/x86/kvm/x86.c:1128 __msr_io arch/x86/kvm/x86.c:2577 [inline] msr_io+0x24b/0x450 arch/x86/kvm/x86.c:2614 kvm_arch_vcpu_ioctl+0x35b/0x46a0 arch/x86/kvm/x86.c:3497 kvm_vcpu_ioctl+0x232/0x1120 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2721 vfs_ioctl fs/ioctl.c:43 [inline] do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683 SYSC_ioctl fs/ioctl.c:698 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689 entry_SYSCALL_64_fastpath+0x1f/0xc2 The syzkaller folks reported a nested_run_pending warning during userspace clear VMX capability which is exposed to L1 before. The warning gets thrown while doing (*(uint32_t*)0x20aecfe8 = (uint32_t)0x1); (*(uint32_t*)0x20aecfec = (uint32_t)0x0); (*(uint32_t*)0x20aecff0 = (uint32_t)0x3a); (*(uint32_t*)0x20aecff4 = (uint32_t)0x0); (*(uint64_t*)0x20aecff8 = (uint64_t)0x0); r[29] = syscall(__NR_ioctl, r[4], 0x4008ae89ul, 0x20aecfe8ul, 0, 0, 0, 0, 0, 0); i.e. KVM_SET_MSR ioctl with struct kvm_msrs { .nmsrs = 1, .pad = 0, .entries = { {.index = MSR_IA32_FEATURE_CONTROL, .reserved = 0, .data = 0} } } The VMLANCH/VMRESUME emulation should be stopped since the CPU is going to reset here. This patch resets the nested_run_pending since the CPU is going to be reset hence there should be nothing pending. Reported-by: Dmitry Vyukov <dvyukov@google.com> Suggested-by: Radim Krčmář <rkrcmar@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: VMX: remove I/O port 0x80 bypass on Intel hostsAndrew Honig2017-12-161-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | commit d59d51f088014f25c2562de59b9abff4f42a7468 upstream. This fixes CVE-2017-1000407. KVM allows guests to directly access I/O port 0x80 on Intel hosts. If the guest floods this port with writes it generates exceptions and instability in the host kernel, leading to a crash. With this change guest writes to port 0x80 on Intel will behave the same as they currently behave on AMD systems. Prevent the flooding by removing the code that sets port 0x80 as a passthrough port. This is essentially the same as upstream patch 99f85a28a78e96d28907fe036e1671a218fee597, except that patch was for AMD chipsets and this patch is for Intel. Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Jim Mattson <jmattson@google.com> Fixes: fdef3ad1b386 ("KVM: VMX: Enable io bitmaps to avoid IO port 0x80 VMEXITs") Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/PCI: Make broadcom_postcore_init() check acpi_disabledRafael J. Wysocki2017-12-161-1/+1
| | | | | | | | | | | | | | | | | | | | | commit ddec3bdee05b06f1dda20ded003c3e10e4184cab upstream. acpi_os_get_root_pointer() may return a valid address even if acpi_disabled is set, but the host bridge information from the ACPI tables is not going to be used in that case and the Broadcom host bridge initialization should not be skipped then, So make broadcom_postcore_init() check acpi_disabled too to avoid this issue. Fixes: 6361d72b04d1 (x86/PCI: read Broadcom CNB20LE host bridge info before PCI scan) Reported-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Linux PCI <linux-pci@vger.kernel.org> Link: https://lkml.kernel.org/r/3186627.pxZj1QbYNg@aspire.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: inject exceptions produced by x86_decode_insnPaolo Bonzini2017-12-051-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 6ea6e84309ca7e0e850b3083e6b09344ee15c290 upstream. Sometimes, a processor might execute an instruction while another processor is updating the page tables for that instruction's code page, but before the TLB shootdown completes. The interesting case happens if the page is in the TLB. In general, the processor will succeed in executing the instruction and nothing bad happens. However, what if the instruction is an MMIO access? If *that* happens, KVM invokes the emulator, and the emulator gets the updated page tables. If the update side had marked the code page as non present, the page table walk then will fail and so will x86_decode_insn. Unfortunately, even though kvm_fetch_guest_virt is correctly returning X86EMUL_PROPAGATE_FAULT, x86_decode_insn's caller treats the failure as a fatal error if the instruction cannot simply be reexecuted (as is the case for MMIO). And this in fact happened sometimes when rebooting Windows 2012r2 guests. Just checking ctxt->have_exception and injecting the exception if true is enough to fix the case. Thanks to Eduardo Habkost for helping in the debugging of this issue. Reported-by: Yanan Fu <yfu@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: Exit to user-mode on #UD intercept when emulator requiresLiran Alon2017-12-052-0/+4
| | | | | | | | | | | | | | | | | | | | commit 61cb57c9ed631c95b54f8e9090c89d18b3695b3c upstream. Instruction emulation after trapping a #UD exception can result in an MMIO access, for example when emulating a MOVBE on a processor that doesn't support the instruction. In this case, the #UD vmexit handler must exit to user mode, but there wasn't any code to do so. Add it for both VMX and SVM. Signed-off-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: SVM: obey guest PATPaolo Bonzini2017-11-301-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 15038e14724799b8c205beb5f20f9e54896013c3 upstream. For many years some users of assigned devices have reported worse performance on AMD processors with NPT than on AMD without NPT, Intel or bare metal. The reason turned out to be that SVM is discarding the guest PAT setting and uses the default (PA0=PA4=WB, PA1=PA5=WT, PA2=PA6=UC-, PA3=UC). The guest might be using a different setting, and especially might want write combining but isn't getting it (instead getting slow UC or UC- accesses). Thanks a lot to geoff@hostfission.com for noticing the relation to the g_pat setting. The patch has been tested also by a bunch of people on VFIO users forums. Fixes: 709ddebf81cb40e3c36c6109a7892e8b93a09464 Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=196409 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Tested-by: Nick Sarnie <commendsarnex@gmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: nVMX: set IDTR and GDTR limits when loading L1 host stateLadi Prosek2017-11-301-0/+2
| | | | | | | | | | | | | commit 21f2d551183847bc7fbe8d866151d00cdad18752 upstream. Intel SDM 27.5.2 Loading Host Segment and Descriptor-Table Registers: "The GDTR and IDTR limits are each set to FFFFH." Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/decoder: Add new TEST instruction patternMasami Hiramatsu2017-11-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 12a78d43de767eaf8fb272facb7a7b6f2dc6a9df upstream. The kbuild test robot reported this build warning: Warning: arch/x86/tools/test_get_len found difference at <jump_table>:ffffffff8103dd2c Warning: ffffffff8103dd82: f6 09 d8 testb $0xd8,(%rcx) Warning: objdump says 3 bytes, but insn_get_length() says 2 Warning: decoded and checked 1569014 instructions with 1 warnings This sequence seems to be a new instruction not in the opcode map in the Intel SDM. The instruction sequence is "F6 09 d8", means Group3(F6), MOD(00)REG(001)RM(001), and 0xd8. Intel SDM vol2 A.4 Table A-6 said the table index in the group is "Encoding of Bits 5,4,3 of the ModR/M Byte (bits 2,1,0 in parenthesis)" In that table, opcodes listed by the index REG bits as: 000 001 010 011 100 101 110 111 TEST Ib/Iz,(undefined),NOT,NEG,MUL AL/rAX,IMUL AL/rAX,DIV AL/rAX,IDIV AL/rAX So, it seems TEST Ib is assigned to 001. Add the new pattern. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* security/keys: add CONFIG_KEYS_COMPAT to KconfigBilal Amarni2017-11-181-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | commit 47b2c3fff4932e6fc17ce13d51a43c6969714e20 upstream. CONFIG_KEYS_COMPAT is defined in arch-specific Kconfigs and is missing for several 64-bit architectures : mips, parisc, tile. At the moment and for those architectures, calling in 32-bit userspace the keyctl syscall would return an ENOSYS error. This patch moves the CONFIG_KEYS_COMPAT option to security/keys/Kconfig, to make sure the compatibility wrapper is registered by default for any 64-bit architecture as long as it is configured with CONFIG_COMPAT. [DH: Modified to remove arm64 compat enablement also as requested by Eric Biggers] Signed-off-by: Bilal Amarni <bilal.amarni@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> cc: Eric Biggers <ebiggers3@gmail.com> Signed-off-by: James Morris <james.l.morris@oracle.com> Cc: James Cowgill <james.cowgill@mips.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/oprofile/ppro: Do not use __this_cpu*() in preemptible contextBorislav Petkov2017-11-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit a743bbeef27b9176987ec0cb7f906ab0ab52d1da upstream. The warning below says it all: BUG: using __this_cpu_read() in preemptible [00000000] code: swapper/0/1 caller is __this_cpu_preempt_check CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-rc8 #4 Call Trace: dump_stack check_preemption_disabled ? do_early_param __this_cpu_preempt_check arch_perfmon_init op_nmi_init ? alloc_pci_root_info oprofile_arch_init oprofile_init do_one_initcall ... These accessors should not have been used in the first place: it is PPro so no mixed silicon revisions and thus it can simply use boot_cpu_data. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Tested-by: Fengguang Wu <fengguang.wu@intel.com> Fix-creation-mandated-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Robert Richter <rric@kernel.org> Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* crypto: x86/sha1-mb - fix panic due to unaligned accessAndrey Ryabinin2017-11-151-6/+6
| | | | | | | | | | | | | | | | | | | | commit d041b557792c85677f17e08eee535eafbd6b9aa2 upstream. struct sha1_ctx_mgr allocated in sha1_mb_mod_init() via kzalloc() and later passed in sha1_mb_flusher_mgr_flush_avx2() function where instructions vmovdqa used to access the struct. vmovdqa requires 16-bytes aligned argument, but nothing guarantees that struct sha1_ctx_mgr will have that alignment. Unaligned vmovdqa will generate GP fault. Fix this by replacing vmovdqa with vmovdqu which doesn't have alignment requirements. Fixes: 2249cbb53ead ("crypto: sha-mb - SHA1 multibuffer submit and flush routines for AVX2") Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/microcode/intel: Disable late loading on model 79Borislav Petkov2017-11-081-0/+18
| | | | | | | | | | | | | | | | | commit 723f2828a98c8ca19842042f418fb30dd8cfc0f7 upstream. Blacklist Broadwell X model 79 for late loading due to an erratum. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Tony Luck <tony.luck@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20171018111225.25635-1-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/mm: Disable preemption during CR3 read+writeSebastian Andrzej Siewior2017-10-211-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 5cf0791da5c162ebc14b01eb01631cfa7ed4fa6e upstream. There's a subtle preemption race on UP kernels: Usually current->mm (and therefore mm->pgd) stays the same during the lifetime of a task so it does not matter if a task gets preempted during the read and write of the CR3. But then, there is this scenario on x86-UP: TaskA is in do_exit() and exit_mm() sets current->mm = NULL followed by: -> mmput() -> exit_mmap() -> tlb_finish_mmu() -> tlb_flush_mmu() -> tlb_flush_mmu_tlbonly() -> tlb_flush() -> flush_tlb_mm_range() -> __flush_tlb_up() -> __flush_tlb() -> __native_flush_tlb() At this point current->mm is NULL but current->active_mm still points to the "old" mm. Let's preempt taskA _after_ native_read_cr3() by taskB. TaskB has its own mm so CR3 has changed. Now preempt back to taskA. TaskA has no ->mm set so it borrows taskB's mm and so CR3 remains unchanged. Once taskA gets active it continues where it was interrupted and that means it writes its old CR3 value back. Everything is fine because userland won't need its memory anymore. Now the fun part: Let's preempt taskA one more time and get back to taskB. This time switch_mm() won't do a thing because oldmm (->active_mm) is the same as mm (as per context_switch()). So we remain with a bad CR3 / PGD and return to userland. The next thing that happens is handle_mm_fault() with an address for the execution of its code in userland. handle_mm_fault() realizes that it has a PTE with proper rights so it returns doing nothing. But the CPU looks at the wrong PGD and insists that something is wrong and faults again. And again. And one more time… This pagefault circle continues until the scheduler gets tired of it and puts another task on the CPU. It gets little difficult if the task is a RT task with a high priority. The system will either freeze or it gets fixed by the software watchdog thread which usually runs at RT-max prio. But waiting for the watchdog will increase the latency of the RT task which is no good. Fix this by disabling preemption across the critical code section. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1470404259-26290-1-git-send-email-bigeasy@linutronix.de [ Prettified the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Bernhard Kaindl <bernhard.kaindl@thalesgroup.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: nVMX: fix guest CR4 loading when emulating L2 to L1 exitHaozhong Zhang2017-10-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 8eb3f87d903168bdbd1222776a6b1e281f50513e upstream. When KVM emulates an exit from L2 to L1, it loads L1 CR4 into the guest CR4. Before this CR4 loading, the guest CR4 refers to L2 CR4. Because these two CR4's are in different levels of guest, we should vmx_set_cr4() rather than kvm_set_cr4() here. The latter, which is used to handle guest writes to its CR4, checks the guest change to CR4 and may fail if the change is invalid. The failure may cause trouble. Consider we start a L1 guest with non-zero L1 PCID in use, (i.e. L1 CR4.PCIDE == 1 && L1 CR3.PCID != 0) and a L2 guest with L2 PCID disabled, (i.e. L2 CR4.PCIDE == 0) and following events may happen: 1. If kvm_set_cr4() is used in load_vmcs12_host_state() to load L1 CR4 into guest CR4 (in VMCS01) for L2 to L1 exit, it will fail because of PCID check. As a result, the guest CR4 recorded in L0 KVM (i.e. vcpu->arch.cr4) is left to the value of L2 CR4. 2. Later, if L1 attempts to change its CR4, e.g., clearing VMXE bit, kvm_set_cr4() in L0 KVM will think L1 also wants to enable PCID, because the wrong L2 CR4 is used by L0 KVM as L1 CR4. As L1 CR3.PCID != 0, L0 KVM will inject GP to L1 guest. Fixes: 4704d0befb072 ("KVM: nVMX: Exiting from L2 to L1") Cc: qemu-stable@nongnu.org Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/fpu: Don't let userspace set bogus xcomp_bvEric Biggers2017-10-052-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 814fb7bb7db5433757d76f4c4502c96fc53b0b5e upstream. [Please apply to 3.18-stable. Note: the backport includes the fpu_finit() call in xstateregs_set(), since fix is useless without it. It was added by commit 91c3dba7dbc1 ("x86/fpu/xstate: Fix PTRACE frames for XSAVES"), but it doesn't make sense to backport that whole commit.] On x86, userspace can use the ptrace() or rt_sigreturn() system calls to set a task's extended state (xstate) or "FPU" registers. ptrace() can set them for another task using the PTRACE_SETREGSET request with NT_X86_XSTATE, while rt_sigreturn() can set them for the current task. In either case, registers can be set to any value, but the kernel assumes that the XSAVE area itself remains valid in the sense that the CPU can restore it. However, in the case where the kernel is using the uncompacted xstate format (which it does whenever the XSAVES instruction is unavailable), it was possible for userspace to set the xcomp_bv field in the xstate_header to an arbitrary value. However, all bits in that field are reserved in the uncompacted case, so when switching to a task with nonzero xcomp_bv, the XRSTOR instruction failed with a #GP fault. This caused the WARN_ON_FPU(err) in copy_kernel_to_xregs() to be hit. In addition, since the error is otherwise ignored, the FPU registers from the task previously executing on the CPU were leaked. Fix the bug by checking that the user-supplied value of xcomp_bv is 0 in the uncompacted case, and returning an error otherwise. The reason for validating xcomp_bv rather than simply overwriting it with 0 is that we want userspace to see an error if it (incorrectly) provides an XSAVE area in compacted format rather than in uncompacted format. Note that as before, in case of error we clear the task's FPU state. This is perhaps non-ideal, especially for PTRACE_SETREGSET; it might be better to return an error before changing anything. But it seems the "clear on error" behavior is fine for now, and it's a little tricky to do otherwise because it would mean we couldn't simply copy the full userspace state into kernel memory in one __copy_from_user(). This bug was found by syzkaller, which hit the above-mentioned WARN_ON_FPU(): WARNING: CPU: 1 PID: 0 at ./arch/x86/include/asm/fpu/internal.h:373 __switch_to+0x5b5/0x5d0 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.13.0 #453 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff9ba2bc8e42c0 task.stack: ffffa78cc036c000 RIP: 0010:__switch_to+0x5b5/0x5d0 RSP: 0000:ffffa78cc08bbb88 EFLAGS: 00010082 RAX: 00000000fffffffe RBX: ffff9ba2b8bf2180 RCX: 00000000c0000100 RDX: 00000000ffffffff RSI: 000000005cb10700 RDI: ffff9ba2b8bf36c0 RBP: ffffa78cc08bbbd0 R08: 00000000929fdf46 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9ba2bc8e42c0 R13: 0000000000000000 R14: ffff9ba2b8bf3680 R15: ffff9ba2bf5d7b40 FS: 00007f7e5cb10700(0000) GS:ffff9ba2bf400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004005cc CR3: 0000000079fd5000 CR4: 00000000001406e0 Call Trace: Code: 84 00 00 00 00 00 e9 11 fd ff ff 0f ff 66 0f 1f 84 00 00 00 00 00 e9 e7 fa ff ff 0f ff 66 0f 1f 84 00 00 00 00 00 e9 c2 fa ff ff <0f> ff 66 0f 1f 84 00 00 00 00 00 e9 d4 fc ff ff 66 66 2e 0f 1f Here is a C reproducer. The expected behavior is that the program spin forever with no output. However, on a buggy kernel running on a processor with the "xsave" feature but without the "xsaves" feature (e.g. Sandy Bridge through Broadwell for Intel), within a second or two the program reports that the xmm registers were corrupted, i.e. were not restored correctly. With CONFIG_X86_DEBUG_FPU=y it also hits the above kernel warning. #define _GNU_SOURCE #include <stdbool.h> #include <inttypes.h> #include <linux/elf.h> #include <stdio.h> #include <sys/ptrace.h> #include <sys/uio.h> #include <sys/wait.h> #include <unistd.h> int main(void) { int pid = fork(); uint64_t xstate[512]; struct iovec iov = { .iov_base = xstate, .iov_len = sizeof(xstate) }; if (pid == 0) { bool tracee = true; for (int i = 0; i < sysconf(_SC_NPROCESSORS_ONLN) && tracee; i++) tracee = (fork() != 0); uint32_t xmm0[4] = { [0 ... 3] = tracee ? 0x00000000 : 0xDEADBEEF }; asm volatile(" movdqu %0, %%xmm0\n" " mov %0, %%rbx\n" "1: movdqu %%xmm0, %0\n" " mov %0, %%rax\n" " cmp %%rax, %%rbx\n" " je 1b\n" : "+m" (xmm0) : : "rax", "rbx", "xmm0"); printf("BUG: xmm registers corrupted! tracee=%d, xmm0=%08X%08X%08X%08X\n", tracee, xmm0[0], xmm0[1], xmm0[2], xmm0[3]); } else { usleep(100000); ptrace(PTRACE_ATTACH, pid, 0, 0); wait(NULL); ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov); xstate[65] = -1; ptrace(PTRACE_SETREGSET, pid, NT_X86_XSTATE, &iov); ptrace(PTRACE_CONT, pid, 0, 0); wait(NULL); } return 1; } Note: the program only tests for the bug using the ptrace() system call. The bug can also be reproduced using the rt_sigreturn() system call, but only when called from a 32-bit program, since for 64-bit programs the kernel restores the FPU state from the signal frame by doing XRSTOR directly from userspace memory (with proper error checking). Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Fixes: 0b29643a5843 ("x86/xsaves: Change compacted format xsave area header") Link: http://lkml.kernel.org/r/20170922174156.16780-2-ebiggers3@gmail.com Link: http://lkml.kernel.org/r/20170923130016.21448-25-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kvm: nVMX: Don't allow L2 to access the hardware CR8Jim Mattson2017-10-051-0/+5
| | | | | | | | | | | | | | | | | commit 51aa68e7d57e3217192d88ce90fd5b8ef29ec94f upstream. If L1 does not specify the "use TPR shadow" VM-execution control in vmcs12, then L0 must specify the "CR8-load exiting" and "CR8-store exiting" VM-execution controls in vmcs02. Failure to do so will give the L2 VM unrestricted read/write access to the hardware CR8. This fixes CVE-2017-12154. Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/tools: Fix gcc-7 warning in relocs.cMarkus Trippelsdorf2017-09-021-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7ebb916782949621ff6819acf373a06902df7679 upstream. gcc-7 warns: In file included from arch/x86/tools/relocs_64.c:17:0: arch/x86/tools/relocs.c: In function ‘process_64’: arch/x86/tools/relocs.c:953:2: warning: argument 1 null where non-null expected [-Wnonnull] qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from arch/x86/tools/relocs.h:6:0, from arch/x86/tools/relocs_64.c:1: /usr/include/stdlib.h:741:13: note: in a call to function ‘qsort’ declared here extern void qsort This happens because relocs16 is not used for ELF_BITS == 64, so there is no point in trying to sort it. Make the sort_relocs(&relocs16) call 32bit only. Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de> Link: http://lkml.kernel.org/r/20161215124513.GA289@x4 Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86-64: Handle PC-relative relocations on per-CPU dataJan Beulich2017-09-022-10/+40
| | | | | | | | | | | | | commit 6d24c5f72dfb26e5fa7f02fa9266dfdbae41adba upstream. This is in preparation of using RIP-relative addressing in many of the per-CPU accesses. Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/5458A15A0200007800044A9A@mail.emea.novell.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/io: Add "memory" clobber to insb/insw/insl/outsb/outsw/outslArnd Bergmann2017-09-021-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7206f9bf108eb9513d170c73f151367a1bdf3dbf upstream. The x86 version of insb/insw/insl uses an inline assembly that does not have the target buffer listed as an output. This can confuse the compiler, leading it to think that a subsequent access of the buffer is uninitialized: drivers/net/wireless/wl3501_cs.c: In function ‘wl3501_mgmt_scan_confirm’: drivers/net/wireless/wl3501_cs.c:665:9: error: ‘sig.status’ is used uninitialized in this function [-Werror=uninitialized] drivers/net/wireless/wl3501_cs.c:668:12: error: ‘sig.cap_info’ may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/net/sb1000.c: In function 'sb1000_rx': drivers/net/sb1000.c:775:9: error: 'st[0]' is used uninitialized in this function [-Werror=uninitialized] drivers/net/sb1000.c:776:10: error: 'st[1]' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/net/sb1000.c:784:11: error: 'st[1]' may be used uninitialized in this function [-Werror=maybe-uninitialized] I tried to mark the exact input buffer as an output here, but couldn't figure it out. As suggested by Linus, marking all memory as clobbered however is good enough too. For the outs operations, I also add the memory clobber, to force the input to be written to local variables. This is probably already guaranteed by the "asm volatile", but it can't hurt to do this for symmetry. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Borislav Petkov <bp@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Link: http://lkml.kernel.org/r/20170719125310.2487451-5-arnd@arndb.de Link: https://lkml.org/lkml/2017/7/12/605 Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/boot: Add missing declaration of string functionsNicholas Mc Guire2017-08-112-0/+10
| | | | | | | | | | | | | | [ Upstream commit fac69d0efad08fc15e4dbfc116830782acc0dc9a ] Add the missing declarations of basic string functions to string.h to allow a clean build. Fixes: 5be865661516 ("String-handling functions for the new x86 setup code.") Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Link: http://lkml.kernel.org/r/1483781911-21399-1-git-send-email-hofrat@osadl.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: async_pf: make rcu irq exit if not triggered from idle taskWanpeng Li2017-08-111-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 337c017ccdf2653d0040099433fc1a2b1beb5926 upstream. WARNING: CPU: 5 PID: 1242 at kernel/rcu/tree_plugin.h:323 rcu_note_context_switch+0x207/0x6b0 CPU: 5 PID: 1242 Comm: unity-settings- Not tainted 4.13.0-rc2+ #1 RIP: 0010:rcu_note_context_switch+0x207/0x6b0 Call Trace: __schedule+0xda/0xba0 ? kvm_async_pf_task_wait+0x1b2/0x270 schedule+0x40/0x90 kvm_async_pf_task_wait+0x1cc/0x270 ? prepare_to_swait+0x22/0x70 do_async_page_fault+0x77/0xb0 ? do_async_page_fault+0x77/0xb0 async_page_fault+0x28/0x30 RIP: 0010:__d_lookup_rcu+0x90/0x1e0 I encounter this when trying to stress the async page fault in L1 guest w/ L2 guests running. Commit 9b132fbe5419 (Add rcu user eqs exception hooks for async page fault) adds rcu_irq_enter/exit() to kvm_async_pf_task_wait() to exit cpu idle eqs when needed, to protect the code that needs use rcu. However, we need to call the pair even if the function calls schedule(), as seen from the above backtrace. This patch fixes it by informing the RCU subsystem exit/enter the irq towards/away from idle for both n.halted and !n.halted. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/mce/AMD: Make the init code more robustThomas Gleixner2017-08-111-0/+3
| | | | | | | | | | | | | | | | [ Upstream commit 0dad3a3014a0b9e72521ff44f17e0054f43dcdea ] If mce_device_init() fails then the mce device pointer is NULL and the AMD mce code happily dereferences it. Add a sanity check. Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/acpi: Prevent out of bound access caused by broken ACPI tablesSeunghun Han2017-07-271-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | commit dad5ab0db8deac535d03e3fe3d8f2892173fa6a4 upstream. The bus_irq argument of mp_override_legacy_irq() is used as the index into the isa_irq_to_gsi[] array. The bus_irq argument originates from ACPI_MADT_TYPE_IO_APIC and ACPI_MADT_TYPE_INTERRUPT items in the ACPI tables, but is nowhere sanity checked. That allows broken or malicious ACPI tables to overwrite memory, which might cause malfunction, panic or arbitrary code execution. Add a sanity check and emit a warning when that triggers. [ tglx: Added warning and rewrote changelog ] Signed-off-by: Seunghun Han <kkamagui@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: security@kernel.org Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/rtc: Remove duplicate const specifierColin King2017-07-271-1/+1
| | | | | | | | | | | | | | | | | | | commit d505ad1d66c9cd31db5ab0d2c7bcb2a47e5bb29e upstream. Building with clang: CC arch/x86/kernel/rtc.o arch/x86/kernel/rtc.c:173:29: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier] static const char * const const ids[] __initconst = Remove the duplicate const, it is not needed and causes a warning. Signed-off-by: Colin Ian King <colin.king@canonical.com> Link: http://lkml.kernel.org/r/1421244475-313-1-git-send-email-colin.king@canonical.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* crypto: sha1-ssse3 - Disable avx2Herbert Xu2017-07-211-1/+1
| | | | | | | | | | | | | | commit b82ce24426a4071da9529d726057e4e642948667 upstream. It has been reported that sha1-avx2 can cause page faults by reading beyond the end of the input. This patch disables it until it can be fixed. Fixes: 7c1da8d0d046 ("crypto: sha - SHA1 transform x86_64 AVX2") Reported-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: nVMX: Fix exception injectionWanpeng Li2017-07-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d4912215d1031e4fb3d1038d2e1857218dba0d0a upstream. WARNING: CPU: 3 PID: 2840 at arch/x86/kvm/vmx.c:10966 nested_vmx_vmexit+0xdcd/0xde0 [kvm_intel] CPU: 3 PID: 2840 Comm: qemu-system-x86 Tainted: G OE 4.12.0-rc3+ #23 RIP: 0010:nested_vmx_vmexit+0xdcd/0xde0 [kvm_intel] Call Trace: ? kvm_check_async_pf_completion+0xef/0x120 [kvm] ? rcu_read_lock_sched_held+0x79/0x80 vmx_queue_exception+0x104/0x160 [kvm_intel] ? vmx_queue_exception+0x104/0x160 [kvm_intel] kvm_arch_vcpu_ioctl_run+0x1171/0x1ce0 [kvm] ? kvm_arch_vcpu_load+0x47/0x240 [kvm] ? kvm_arch_vcpu_load+0x62/0x240 [kvm] kvm_vcpu_ioctl+0x384/0x7b0 [kvm] ? kvm_vcpu_ioctl+0x384/0x7b0 [kvm] ? __fget+0xf3/0x210 do_vfs_ioctl+0xa4/0x700 ? __fget+0x114/0x210 SyS_ioctl+0x79/0x90 do_syscall_64+0x81/0x220 entry_SYSCALL64_slow_path+0x25/0x25 This is triggered occasionally by running both win7 and win2016 in L2, in addition, EPT is disabled on both L1 and L2. It can't be reproduced easily. Commit 0b6ac343fc (KVM: nVMX: Correct handling of exception injection) mentioned that "KVM wants to inject page-faults which it got to the guest. This function assumes it is called with the exit reason in vmcs02 being a #PF exception". Commit e011c663 (KVM: nVMX: Check all exceptions for intercept during delivery to L2) allows to check all exceptions for intercept during delivery to L2. However, there is no guarantee the exit reason is exception currently, when there is an external interrupt occurred on host, maybe a time interrupt for host which should not be injected to guest, and somewhere queues an exception, then the function nested_vmx_check_exception() will be called and the vmexit emulation codes will try to emulate the "Acknowledge interrupt on exit" behavior, the warning is triggered. Reusing the exit reason from the L2->L0 vmexit is wrong in this case, the reason must always be EXCEPTION_NMI when injecting an exception into L1 as a nested vmexit. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Fixes: e011c663b9c7 ("KVM: nVMX: Check all exceptions for intercept during delivery to L2") Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: x86: zero base3 of unusable segmentsRadim Krčmář2017-07-051-0/+2
| | | | | | | | | | | | | | | | commit f0367ee1d64d27fa08be2407df5c125442e885e3 upstream. Static checker noticed that base3 could be used uninitialized if the segment was not present (useable). Random stack values probably would not pass VMCS entry checks. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 1aa366163b8b ("KVM: x86 emulator: consolidate segment accessors") Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm: larger stack guard gap, between vmasHugh Dickins2017-06-262-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream. Stack guard page is a useful feature to reduce a risk of stack smashing into a different mapping. We have been using a single page gap which is sufficient to prevent having stack adjacent to a different mapping. But this seems to be insufficient in the light of the stack usage in userspace. E.g. glibc uses as large as 64kB alloca() in many commonly used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] which is 256kB or stack strings with MAX_ARG_STRLEN. This will become especially dangerous for suid binaries and the default no limit for the stack size limit because those applications can be tricked to consume a large portion of the stack and a single glibc call could jump over the guard page. These attacks are not theoretical, unfortunatelly. Make those attacks less probable by increasing the stack guard gap to 1MB (on systems with 4k pages; but make it depend on the page size because systems with larger base pages might cap stack allocations in the PAGE_SIZE units) which should cover larger alloca() and VLA stack allocations. It is obviously not a full fix because the problem is somehow inherent, but it should reduce attack space a lot. One could argue that the gap size should be configurable from userspace, but that can be done later when somebody finds that the new 1MB is wrong for some special case applications. For now, add a kernel command line option (stack_guard_gap) to specify the stack gap size (in page units). Implementation wise, first delete all the old code for stack guard page: because although we could get away with accounting one extra page in a stack vma, accounting a larger gap can break userspace - case in point, a program run with "ulimit -S -v 20000" failed when the 1MB gap was counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK and strict non-overcommit mode. Instead of keeping gap inside the stack vma, maintain the stack guard gap as a gap between vmas: using vm_start_gap() in place of vm_start (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few places which need to respect the gap - mainly arch_get_unmapped_area(), and and the vma tree's subtree_gap support for that. Original-patch-by: Oleg Nesterov <oleg@redhat.com> Original-patch-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Tested-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [wt: backport to 4.11: adjust context] [wt: backport to 4.9: adjust context ; kernel doc was not in admin-guide] [wt: backport to 4.4: adjust context ; drop ppc hugetlb_radix changes] [wt: backport to 3.18: adjust context ; no FOLL_POPULATE ; s390 uses generic arch_get_unmapped_area()] Signed-off-by: Willy Tarreau <w@1wt.eu> [gkh: minor build fixes for 3.18] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/mm/32: Set the '__vmalloc_start_set' flag in initmem_init()Laura Abbott2017-06-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | commit 861ce4a3244c21b0af64f880d5bfe5e6e2fb9e4a upstream. '__vmalloc_start_set' currently only gets set in initmem_init() when !CONFIG_NEED_MULTIPLE_NODES. This breaks detection of vmalloc address with virt_addr_valid() with CONFIG_NEED_MULTIPLE_NODES=y, causing a kernel crash: [mm/usercopy] 517e1fbeb6: kernel BUG at arch/x86/mm/physaddr.c:78! Set '__vmalloc_start_set' appropriately for that case as well. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Laura Abbott <labbott@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: dc16ecf7fd1f ("x86-32: use specific __vmalloc_start_set flag in __virt_addr_valid") Link: http://lkml.kernel.org/r/1494278596-30373-1-git-send-email-labbott@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: cpuid: Fix read/write out-of-bounds vulnerability in cpuid emulationWanpeng Li2017-06-141-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit a3641631d14571242eec0d30c9faa786cbf52d44 upstream. If "i" is the last element in the vcpu->arch.cpuid_entries[] array, it potentially can be exploited the vulnerability. this will out-of-bounds read and write. Luckily, the effect is small: /* when no next entry is found, the current entry[i] is reselected */ for (j = i + 1; ; j = (j + 1) % nent) { struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j]; if (ej->function == e->function) { It reads ej->maxphyaddr, which is user controlled. However... ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; After cpuid_entries there is int maxphyaddr; struct x86_emulate_ctxt emulate_ctxt; /* 16-byte aligned */ So we have: - cpuid_entries at offset 1B50 (6992) - maxphyaddr at offset 27D0 (6992 + 3200 = 10192) - padding at 27D4...27DF - emulate_ctxt at 27E0 And it writes in the padding. Pfew, writing the ops field of emulate_ctxt would have been much worse. This patch fixes it by modding the index to avoid the out-of-bounds access. Worst case, i == j and ej->function == e->function, the loop can bail out. Reported-by: Moguofang <moguofang@huawei.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Guofang Mo <moguofang@huawei.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kvm: async_pf: fix rcu_irq_enter() with irqs enabledPaolo Bonzini2017-06-141-1/+1
| | | | | | | | | | | | | | | | | commit bbaf0e2b1c1b4f88abd6ef49576f0efb1734eae5 upstream. native_safe_halt enables interrupts, and you just shouldn't call rcu_irq_enter() with interrupts enabled. Reorder the call with the following local_irq_disable() to respect the invariant. Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* um: Fix PTRACE_POKEUSER on x86_64Richard Weinberger2017-05-201-1/+1
| | | | | | | | | | | | | | | | | commit 9abc74a22d85ab29cef9896a2582a530da7e79bf upstream. This is broken since ever but sadly nobody noticed. Recent versions of GDB set DR_CONTROL unconditionally and UML dies due to a heap corruption. It turns out that the PTRACE_POKEUSER was copy&pasted from i386 and assumes that addresses are 4 bytes long. Fix that by using 8 as address size in the calculation. Reported-by: jie cao <cj3054@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/boot: Fix BSS corruption/overwrite bug in early x86 kernel startupAshish Kalra2017-05-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d594aa0277e541bb997aef0bc0a55172d8138340 upstream. The minimum size for a new stack (512 bytes) setup for arch/x86/boot components when the bootloader does not setup/provide a stack for the early boot components is not "enough". The setup code executing as part of early kernel startup code, uses the stack beyond 512 bytes and accidentally overwrites and corrupts part of the BSS section. This is exposed mostly in the early video setup code, where it was corrupting BSS variables like force_x, force_y, which in-turn affected kernel parameters such as screen_info (screen_info.orig_video_cols) and later caused an exception/panic in console_init(). Most recent boot loaders setup the stack for early boot components, so this stack overwriting into BSS section issue has not been exposed. Signed-off-by: Ashish Kalra <ashish@bluestacks.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170419152015.10011-1-ashishkalra@Ashishs-MacBook-Pro.local Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "KVM: nested VMX: disable perf cpuid reporting"Jim Mattson2017-05-152-8/+0
| | | | | | | | | | | | | | | | | commit 0b4c208d443ba2af82b4c70f99ca8df31e9a0020 upstream. This reverts commit bc6134942dbbf31c25e9bd7c876be5da81c9e1ce. A CPUID instruction executed in VMX non-root mode always causes a VM-exit, regardless of the leaf being queried. Fixes: bc6134942dbb ("KVM: nested VMX: disable perf cpuid reporting") Signed-off-by: Jim Mattson <jmattson@google.com> [The issue solved by bc6134942dbb has been resolved with ff651cb613b4 ("KVM: nVMX: Add nested msr load/restore algorithm").] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/platform/intel-mid: Correct MSI IRQ line for watchdog deviceAndy Shevchenko2017-05-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | commit 80354c29025833acd72ddac1ffa21c6cb50128cd upstream. The interrupt line used for the watchdog is 12, according to the official Intel Edison BSP code. And indeed after fixing it we start getting an interrupt and thus the watchdog starts working again: [ 191.699951] Kernel panic - not syncing: Kernel Watchdog Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: David Cohen <david.a.cohen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 78a3bb9e408b ("x86: intel-mid: add watchdog platform code for Merrifield") Link: http://lkml.kernel.org/r/20170312150744.45493-1-andriy.shevchenko@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kprobes/x86: Fix kernel panic when certain exception-handling addresses are ↵Masami Hiramatsu2017-05-153-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | probed commit 75013fb16f8484898eaa8d0b08fed942d790f029 upstream. Fix to the exception table entry check by using probed address instead of the address of copied instruction. This bug may cause unexpected kernel panic if user probe an address where an exception can happen which should be fixup by __ex_table (e.g. copy_from_user.) Unless user puts a kprobe on such address, this doesn't cause any problem. This bug has been introduced years ago, by commit: 464846888d9a ("x86/kprobes: Fix a bug which can modify kernel code permanently"). Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 464846888d9a ("x86/kprobes: Fix a bug which can modify kernel code permanently") Link: http://lkml.kernel.org/r/148829899399.28855.12581062400757221722.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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