April 2022 - Linux-stable-mirror

FAILED: patch "[PATCH] KVM: SEV: add cache flush to solve SEV cache incoherency" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 683412ccf61294d727ead4a73d97397396e69a6b Mon Sep 17 00:00:00 2001 From: Mingwei Zhang <mizhang(a)google.com> Date: Thu, 21 Apr 2022 03:14:07 +0000 Subject: [PATCH] KVM: SEV: add cache flush to solve SEV cache incoherency issues Flush the CPU caches when memory is reclaimed from an SEV guest (where reclaim also includes it being unmapped from KVM's memslots). Due to lack of coherency for SEV encrypted memory, failure to flush results in silent data corruption if userspace is malicious/broken and doesn't ensure SEV guest memory is properly pinned and unpinned. Cache coherency is not enforced across the VM boundary in SEV (AMD APM vol.2 Section 15.34.7). Confidential cachelines, generated by confidential VM guests have to be explicitly flushed on the host side. If a memory page containing dirty confidential cachelines was released by VM and reallocated to another user, the cachelines may corrupt the new user at a later time. KVM takes a shortcut by assuming all confidential memory remain pinned until the end of VM lifetime. Therefore, KVM does not flush cache at mmu_notifier invalidation events. Because of this incorrect assumption and the lack of cache flushing, malicous userspace can crash the host kernel: creating a malicious VM and continuously allocates/releases unpinned confidential memory pages when the VM is running. Add cache flush operations to mmu_notifier operations to ensure that any physical memory leaving the guest VM get flushed. In particular, hook mmu_notifier_invalidate_range_start and mmu_notifier_release events and flush cache accordingly. The hook after releasing the mmu lock to avoid contention with other vCPUs. Cc: stable(a)vger.kernel.org Suggested-by: Sean Christpherson <seanjc(a)google.com> Reported-by: Mingwei Zhang <mizhang(a)google.com> Signed-off-by: Mingwei Zhang <mizhang(a)google.com> Message-Id: <20220421031407.2516575-4-mizhang(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index 3c368b639c04..1a6d7e3f6c32 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -118,6 +118,7 @@ KVM_X86_OP_OPTIONAL(mem_enc_register_region) KVM_X86_OP_OPTIONAL(mem_enc_unregister_region) KVM_X86_OP_OPTIONAL(vm_copy_enc_context_from) KVM_X86_OP_OPTIONAL(vm_move_enc_context_from) +KVM_X86_OP_OPTIONAL(guest_memory_reclaimed) KVM_X86_OP(get_msr_feature) KVM_X86_OP(can_emulate_instruction) KVM_X86_OP(apic_init_signal_blocked) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index e0c0f0e1f754..4ff36610af6a 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1484,6 +1484,7 @@ struct kvm_x86_ops { int (*mem_enc_unregister_region)(struct kvm *kvm, struct kvm_enc_region *argp); int (*vm_copy_enc_context_from)(struct kvm *kvm, unsigned int source_fd); int (*vm_move_enc_context_from)(struct kvm *kvm, unsigned int source_fd); + void (*guest_memory_reclaimed)(struct kvm *kvm); int (*get_msr_feature)(struct kvm_msr_entry *entry); diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 9a0375987029..0ad70c12c7c3 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2262,6 +2262,14 @@ do_wbinvd: wbinvd_on_all_cpus(); } +void sev_guest_memory_reclaimed(struct kvm *kvm) +{ + if (!sev_guest(kvm)) + return; + + wbinvd_on_all_cpus(); +} + void sev_free_vcpu(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm; diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index bd4c64b362d2..7e45d03cd018 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4620,6 +4620,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = { .mem_enc_ioctl = sev_mem_enc_ioctl, .mem_enc_register_region = sev_mem_enc_register_region, .mem_enc_unregister_region = sev_mem_enc_unregister_region, + .guest_memory_reclaimed = sev_guest_memory_reclaimed, .vm_copy_enc_context_from = sev_vm_copy_enc_context_from, .vm_move_enc_context_from = sev_vm_move_enc_context_from, diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index f77a7d2d39dd..f76deff71002 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -609,6 +609,8 @@ int sev_mem_enc_unregister_region(struct kvm *kvm, struct kvm_enc_region *range); int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd); int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd); +void sev_guest_memory_reclaimed(struct kvm *kvm); + void pre_sev_run(struct vcpu_svm *svm, int cpu); void __init sev_set_cpu_caps(void); void __init sev_hardware_setup(void); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c89dc09a764f..a6ab19afc638 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9889,6 +9889,11 @@ void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm, kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD); } +void kvm_arch_guest_memory_reclaimed(struct kvm *kvm) +{ + static_call_cond(kvm_x86_guest_memory_reclaimed)(kvm); +} + static void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu) { if (!lapic_in_kernel(vcpu)) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 2dab4b696682..34eed5f85ed6 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -2219,6 +2219,8 @@ static inline long kvm_arch_vcpu_async_ioctl(struct file *filp, void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm, unsigned long start, unsigned long end); +void kvm_arch_guest_memory_reclaimed(struct kvm *kvm); + #ifdef CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu); #else diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 2a23f24d13cf..f30bb8c16f26 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -164,6 +164,10 @@ __weak void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm, { } +__weak void kvm_arch_guest_memory_reclaimed(struct kvm *kvm) +{ +} + bool kvm_is_zone_device_pfn(kvm_pfn_t pfn) { /* @@ -357,6 +361,12 @@ void kvm_flush_remote_tlbs(struct kvm *kvm) EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs); #endif +static void kvm_flush_shadow_all(struct kvm *kvm) +{ + kvm_arch_flush_shadow_all(kvm); + kvm_arch_guest_memory_reclaimed(kvm); +} + #ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc, gfp_t gfp_flags) @@ -485,12 +495,15 @@ typedef bool (*hva_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range); typedef void (*on_lock_fn_t)(struct kvm *kvm, unsigned long start, unsigned long end); +typedef void (*on_unlock_fn_t)(struct kvm *kvm); + struct kvm_hva_range { unsigned long start; unsigned long end; pte_t pte; hva_handler_t handler; on_lock_fn_t on_lock; + on_unlock_fn_t on_unlock; bool flush_on_ret; bool may_block; }; @@ -578,8 +591,11 @@ static __always_inline int __kvm_handle_hva_range(struct kvm *kvm, if (range->flush_on_ret && ret) kvm_flush_remote_tlbs(kvm); - if (locked) + if (locked) { KVM_MMU_UNLOCK(kvm); + if (!IS_KVM_NULL_FN(range->on_unlock)) + range->on_unlock(kvm); + } srcu_read_unlock(&kvm->srcu, idx); @@ -600,6 +616,7 @@ static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn, .pte = pte, .handler = handler, .on_lock = (void *)kvm_null_fn, + .on_unlock = (void *)kvm_null_fn, .flush_on_ret = true, .may_block = false, }; @@ -619,6 +636,7 @@ static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn .pte = __pte(0), .handler = handler, .on_lock = (void *)kvm_null_fn, + .on_unlock = (void *)kvm_null_fn, .flush_on_ret = false, .may_block = false, }; @@ -687,6 +705,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, .pte = __pte(0), .handler = kvm_unmap_gfn_range, .on_lock = kvm_inc_notifier_count, + .on_unlock = kvm_arch_guest_memory_reclaimed, .flush_on_ret = true, .may_block = mmu_notifier_range_blockable(range), }; @@ -741,6 +760,7 @@ static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn, .pte = __pte(0), .handler = (void *)kvm_null_fn, .on_lock = kvm_dec_notifier_count, + .on_unlock = (void *)kvm_null_fn, .flush_on_ret = false, .may_block = mmu_notifier_range_blockable(range), }; @@ -813,7 +833,7 @@ static void kvm_mmu_notifier_release(struct mmu_notifier *mn, int idx; idx = srcu_read_lock(&kvm->srcu); - kvm_arch_flush_shadow_all(kvm); + kvm_flush_shadow_all(kvm); srcu_read_unlock(&kvm->srcu, idx); } @@ -1225,7 +1245,7 @@ static void kvm_destroy_vm(struct kvm *kvm) WARN_ON(rcuwait_active(&kvm->mn_memslots_update_rcuwait)); kvm->mn_active_invalidate_count = 0; #else - kvm_arch_flush_shadow_all(kvm); + kvm_flush_shadow_all(kvm); #endif kvm_arch_destroy_vm(kvm); kvm_destroy_devices(kvm); @@ -1652,6 +1672,7 @@ static void kvm_invalidate_memslot(struct kvm *kvm, * - kvm_is_visible_gfn (mmu_check_root) */ kvm_arch_flush_shadow_memslot(kvm, old); + kvm_arch_guest_memory_reclaimed(kvm); /* Was released by kvm_swap_active_memslots, reacquire. */ mutex_lock(&kvm->slots_arch_lock);

2 years, 8 months

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FAILED: patch "[PATCH] KVM: SEV: add cache flush to solve SEV cache incoherency" failed to apply to 5.17-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.17-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 683412ccf61294d727ead4a73d97397396e69a6b Mon Sep 17 00:00:00 2001 From: Mingwei Zhang <mizhang(a)google.com> Date: Thu, 21 Apr 2022 03:14:07 +0000 Subject: [PATCH] KVM: SEV: add cache flush to solve SEV cache incoherency issues Flush the CPU caches when memory is reclaimed from an SEV guest (where reclaim also includes it being unmapped from KVM's memslots). Due to lack of coherency for SEV encrypted memory, failure to flush results in silent data corruption if userspace is malicious/broken and doesn't ensure SEV guest memory is properly pinned and unpinned. Cache coherency is not enforced across the VM boundary in SEV (AMD APM vol.2 Section 15.34.7). Confidential cachelines, generated by confidential VM guests have to be explicitly flushed on the host side. If a memory page containing dirty confidential cachelines was released by VM and reallocated to another user, the cachelines may corrupt the new user at a later time. KVM takes a shortcut by assuming all confidential memory remain pinned until the end of VM lifetime. Therefore, KVM does not flush cache at mmu_notifier invalidation events. Because of this incorrect assumption and the lack of cache flushing, malicous userspace can crash the host kernel: creating a malicious VM and continuously allocates/releases unpinned confidential memory pages when the VM is running. Add cache flush operations to mmu_notifier operations to ensure that any physical memory leaving the guest VM get flushed. In particular, hook mmu_notifier_invalidate_range_start and mmu_notifier_release events and flush cache accordingly. The hook after releasing the mmu lock to avoid contention with other vCPUs. Cc: stable(a)vger.kernel.org Suggested-by: Sean Christpherson <seanjc(a)google.com> Reported-by: Mingwei Zhang <mizhang(a)google.com> Signed-off-by: Mingwei Zhang <mizhang(a)google.com> Message-Id: <20220421031407.2516575-4-mizhang(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index 3c368b639c04..1a6d7e3f6c32 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -118,6 +118,7 @@ KVM_X86_OP_OPTIONAL(mem_enc_register_region) KVM_X86_OP_OPTIONAL(mem_enc_unregister_region) KVM_X86_OP_OPTIONAL(vm_copy_enc_context_from) KVM_X86_OP_OPTIONAL(vm_move_enc_context_from) +KVM_X86_OP_OPTIONAL(guest_memory_reclaimed) KVM_X86_OP(get_msr_feature) KVM_X86_OP(can_emulate_instruction) KVM_X86_OP(apic_init_signal_blocked) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index e0c0f0e1f754..4ff36610af6a 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1484,6 +1484,7 @@ struct kvm_x86_ops { int (*mem_enc_unregister_region)(struct kvm *kvm, struct kvm_enc_region *argp); int (*vm_copy_enc_context_from)(struct kvm *kvm, unsigned int source_fd); int (*vm_move_enc_context_from)(struct kvm *kvm, unsigned int source_fd); + void (*guest_memory_reclaimed)(struct kvm *kvm); int (*get_msr_feature)(struct kvm_msr_entry *entry); diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 9a0375987029..0ad70c12c7c3 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2262,6 +2262,14 @@ do_wbinvd: wbinvd_on_all_cpus(); } +void sev_guest_memory_reclaimed(struct kvm *kvm) +{ + if (!sev_guest(kvm)) + return; + + wbinvd_on_all_cpus(); +} + void sev_free_vcpu(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm; diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index bd4c64b362d2..7e45d03cd018 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4620,6 +4620,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = { .mem_enc_ioctl = sev_mem_enc_ioctl, .mem_enc_register_region = sev_mem_enc_register_region, .mem_enc_unregister_region = sev_mem_enc_unregister_region, + .guest_memory_reclaimed = sev_guest_memory_reclaimed, .vm_copy_enc_context_from = sev_vm_copy_enc_context_from, .vm_move_enc_context_from = sev_vm_move_enc_context_from, diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index f77a7d2d39dd..f76deff71002 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -609,6 +609,8 @@ int sev_mem_enc_unregister_region(struct kvm *kvm, struct kvm_enc_region *range); int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd); int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd); +void sev_guest_memory_reclaimed(struct kvm *kvm); + void pre_sev_run(struct vcpu_svm *svm, int cpu); void __init sev_set_cpu_caps(void); void __init sev_hardware_setup(void); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c89dc09a764f..a6ab19afc638 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9889,6 +9889,11 @@ void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm, kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD); } +void kvm_arch_guest_memory_reclaimed(struct kvm *kvm) +{ + static_call_cond(kvm_x86_guest_memory_reclaimed)(kvm); +} + static void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu) { if (!lapic_in_kernel(vcpu)) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 2dab4b696682..34eed5f85ed6 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -2219,6 +2219,8 @@ static inline long kvm_arch_vcpu_async_ioctl(struct file *filp, void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm, unsigned long start, unsigned long end); +void kvm_arch_guest_memory_reclaimed(struct kvm *kvm); + #ifdef CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu); #else diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 2a23f24d13cf..f30bb8c16f26 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -164,6 +164,10 @@ __weak void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm, { } +__weak void kvm_arch_guest_memory_reclaimed(struct kvm *kvm) +{ +} + bool kvm_is_zone_device_pfn(kvm_pfn_t pfn) { /* @@ -357,6 +361,12 @@ void kvm_flush_remote_tlbs(struct kvm *kvm) EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs); #endif +static void kvm_flush_shadow_all(struct kvm *kvm) +{ + kvm_arch_flush_shadow_all(kvm); + kvm_arch_guest_memory_reclaimed(kvm); +} + #ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc, gfp_t gfp_flags) @@ -485,12 +495,15 @@ typedef bool (*hva_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range); typedef void (*on_lock_fn_t)(struct kvm *kvm, unsigned long start, unsigned long end); +typedef void (*on_unlock_fn_t)(struct kvm *kvm); + struct kvm_hva_range { unsigned long start; unsigned long end; pte_t pte; hva_handler_t handler; on_lock_fn_t on_lock; + on_unlock_fn_t on_unlock; bool flush_on_ret; bool may_block; }; @@ -578,8 +591,11 @@ static __always_inline int __kvm_handle_hva_range(struct kvm *kvm, if (range->flush_on_ret && ret) kvm_flush_remote_tlbs(kvm); - if (locked) + if (locked) { KVM_MMU_UNLOCK(kvm); + if (!IS_KVM_NULL_FN(range->on_unlock)) + range->on_unlock(kvm); + } srcu_read_unlock(&kvm->srcu, idx); @@ -600,6 +616,7 @@ static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn, .pte = pte, .handler = handler, .on_lock = (void *)kvm_null_fn, + .on_unlock = (void *)kvm_null_fn, .flush_on_ret = true, .may_block = false, }; @@ -619,6 +636,7 @@ static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn .pte = __pte(0), .handler = handler, .on_lock = (void *)kvm_null_fn, + .on_unlock = (void *)kvm_null_fn, .flush_on_ret = false, .may_block = false, }; @@ -687,6 +705,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, .pte = __pte(0), .handler = kvm_unmap_gfn_range, .on_lock = kvm_inc_notifier_count, + .on_unlock = kvm_arch_guest_memory_reclaimed, .flush_on_ret = true, .may_block = mmu_notifier_range_blockable(range), }; @@ -741,6 +760,7 @@ static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn, .pte = __pte(0), .handler = (void *)kvm_null_fn, .on_lock = kvm_dec_notifier_count, + .on_unlock = (void *)kvm_null_fn, .flush_on_ret = false, .may_block = mmu_notifier_range_blockable(range), }; @@ -813,7 +833,7 @@ static void kvm_mmu_notifier_release(struct mmu_notifier *mn, int idx; idx = srcu_read_lock(&kvm->srcu); - kvm_arch_flush_shadow_all(kvm); + kvm_flush_shadow_all(kvm); srcu_read_unlock(&kvm->srcu, idx); } @@ -1225,7 +1245,7 @@ static void kvm_destroy_vm(struct kvm *kvm) WARN_ON(rcuwait_active(&kvm->mn_memslots_update_rcuwait)); kvm->mn_active_invalidate_count = 0; #else - kvm_arch_flush_shadow_all(kvm); + kvm_flush_shadow_all(kvm); #endif kvm_arch_destroy_vm(kvm); kvm_destroy_devices(kvm); @@ -1652,6 +1672,7 @@ static void kvm_invalidate_memslot(struct kvm *kvm, * - kvm_is_visible_gfn (mmu_check_root) */ kvm_arch_flush_shadow_memslot(kvm, old); + kvm_arch_guest_memory_reclaimed(kvm); /* Was released by kvm_swap_active_memslots, reacquire. */ mutex_lock(&kvm->slots_arch_lock);

2 years, 8 months

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FAILED: patch "[PATCH] KVM: SVM: Simplify and harden helper to flush SEV guest" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 4bbef7e8eb8c2c7dabf57d97decfd2b4f48aaf02 Mon Sep 17 00:00:00 2001 From: Sean Christopherson <seanjc(a)google.com> Date: Thu, 21 Apr 2022 03:14:05 +0000 Subject: [PATCH] KVM: SVM: Simplify and harden helper to flush SEV guest page(s) Rework sev_flush_guest_memory() to explicitly handle only a single page, and harden it to fall back to WBINVD if VM_PAGE_FLUSH fails. Per-page flushing is currently used only to flush the VMSA, and in its current form, the helper is completely broken with respect to flushing actual guest memory, i.e. won't work correctly for an arbitrary memory range. VM_PAGE_FLUSH takes a host virtual address, and is subject to normal page walks, i.e. will fault if the address is not present in the host page tables or does not have the correct permissions. Current AMD CPUs also do not honor SMAP overrides (undocumented in kernel versions of the APM), so passing in a userspace address is completely out of the question. In other words, KVM would need to manually walk the host page tables to get the pfn, ensure the pfn is stable, and then use the direct map to invoke VM_PAGE_FLUSH. And the latter might not even work, e.g. if userspace is particularly evil/clever and backs the guest with Secret Memory (which unmaps memory from the direct map). Signed-off-by: Sean Christopherson <seanjc(a)google.com> Fixes: add5e2f04541 ("KVM: SVM: Add support for the SEV-ES VMSA") Reported-by: Mingwei Zhang <mizhang(a)google.com> Cc: stable(a)vger.kernel.org Signed-off-by: Mingwei Zhang <mizhang(a)google.com> Message-Id: <20220421031407.2516575-2-mizhang(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 537aaddc852f..b77b3913e2d9 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2226,9 +2226,18 @@ int sev_cpu_init(struct svm_cpu_data *sd) * Pages used by hardware to hold guest encrypted state must be flushed before * returning them to the system. */ -static void sev_flush_guest_memory(struct vcpu_svm *svm, void *va, - unsigned long len) +static void sev_flush_encrypted_page(struct kvm_vcpu *vcpu, void *va) { + int asid = to_kvm_svm(vcpu->kvm)->sev_info.asid; + + /* + * Note! The address must be a kernel address, as regular page walk + * checks are performed by VM_PAGE_FLUSH, i.e. operating on a user + * address is non-deterministic and unsafe. This function deliberately + * takes a pointer to deter passing in a user address. + */ + unsigned long addr = (unsigned long)va; + /* * If hardware enforced cache coherency for encrypted mappings of the * same physical page is supported, nothing to do. @@ -2237,40 +2246,16 @@ static void sev_flush_guest_memory(struct vcpu_svm *svm, void *va, return; /* - * If the VM Page Flush MSR is supported, use it to flush the page - * (using the page virtual address and the guest ASID). + * VM Page Flush takes a host virtual address and a guest ASID. Fall + * back to WBINVD if this faults so as not to make any problems worse + * by leaving stale encrypted data in the cache. */ - if (boot_cpu_has(X86_FEATURE_VM_PAGE_FLUSH)) { - struct kvm_sev_info *sev; - unsigned long va_start; - u64 start, stop; + if (WARN_ON_ONCE(wrmsrl_safe(MSR_AMD64_VM_PAGE_FLUSH, addr | asid))) + goto do_wbinvd; - /* Align start and stop to page boundaries. */ - va_start = (unsigned long)va; - start = (u64)va_start & PAGE_MASK; - stop = PAGE_ALIGN((u64)va_start + len); - - if (start < stop) { - sev = &to_kvm_svm(svm->vcpu.kvm)->sev_info; - - while (start < stop) { - wrmsrl(MSR_AMD64_VM_PAGE_FLUSH, - start | sev->asid); - - start += PAGE_SIZE; - } + return; - return; - } - - WARN(1, "Address overflow, using WBINVD\n"); - } - - /* - * Hardware should always have one of the above features, - * but if not, use WBINVD and issue a warning. - */ - WARN_ONCE(1, "Using WBINVD to flush guest memory\n"); +do_wbinvd: wbinvd_on_all_cpus(); } @@ -2284,7 +2269,8 @@ void sev_free_vcpu(struct kvm_vcpu *vcpu) svm = to_svm(vcpu); if (vcpu->arch.guest_state_protected) - sev_flush_guest_memory(svm, svm->sev_es.vmsa, PAGE_SIZE); + sev_flush_encrypted_page(vcpu, svm->sev_es.vmsa); + __free_page(virt_to_page(svm->sev_es.vmsa)); if (svm->sev_es.ghcb_sa_free)

2 years, 8 months

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FAILED: patch "[PATCH] KVM: nVMX: Defer APICv updates while L2 is active until L1 is" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7c69661e225cc484fbf44a0b99b56714a5241ae3 Mon Sep 17 00:00:00 2001 From: Sean Christopherson <seanjc(a)google.com> Date: Wed, 20 Apr 2022 01:37:30 +0000 Subject: [PATCH] KVM: nVMX: Defer APICv updates while L2 is active until L1 is active Defer APICv updates that occur while L2 is active until nested VM-Exit, i.e. until L1 regains control. vmx_refresh_apicv_exec_ctrl() assumes L1 is active and (a) stomps all over vmcs02 and (b) neglects to ever updated vmcs01. E.g. if vmcs12 doesn't enable the TPR shadow for L2 (and thus no APICv controls), L1 performs nested VM-Enter APICv inhibited, and APICv becomes unhibited while L2 is active, KVM will set various APICv controls in vmcs02 and trigger a failed VM-Entry. The kicker is that, unless running with nested_early_check=1, KVM blames L1 and chaos ensues. In all cases, ignoring vmcs02 and always deferring the inhibition change to vmcs01 is correct (or at least acceptable). The ABSENT and DISABLE inhibitions cannot truly change while L2 is active (see below). IRQ_BLOCKING can change, but it is firmly a best effort debug feature. Furthermore, only L2's APIC is accelerated/virtualized to the full extent possible, e.g. even if L1 passes through its APIC to L2, normal MMIO/MSR interception will apply to the virtual APIC managed by KVM. The exception is the SELF_IPI register when x2APIC is enabled, but that's an acceptable hole. Lastly, Hyper-V's Auto EOI can technically be toggled if L1 exposes the MSRs to L2, but for that to work in any sane capacity, L1 would need to pass through IRQs to L2 as well, and IRQs must be intercepted to enable virtual interrupt delivery. I.e. exposing Auto EOI to L2 and enabling VID for L2 are, for all intents and purposes, mutually exclusive. Lack of dynamic toggling is also why this scenario is all but impossible to encounter in KVM's current form. But a future patch will pend an APICv update request _during_ vCPU creation to plug a race where a vCPU that's being created doesn't get included in the "all vCPUs request" because it's not yet visible to other vCPUs. If userspaces restores L2 after VM creation (hello, KVM selftests), the first KVM_RUN will occur while L2 is active and thus service the APICv update request made during VM creation. Cc: stable(a)vger.kernel.org Signed-off-by: Sean Christopherson <seanjc(a)google.com> Message-Id: <20220420013732.3308816-3-seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index f18744f7ff82..856c87563883 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -4618,6 +4618,11 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason, kvm_make_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu); } + if (vmx->nested.update_vmcs01_apicv_status) { + vmx->nested.update_vmcs01_apicv_status = false; + kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu); + } + if ((vm_exit_reason != -1) && (enable_shadow_vmcs || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))) vmx->nested.need_vmcs12_to_shadow_sync = true; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 04d170c4b61e..d58b763df855 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4174,6 +4174,11 @@ static void vmx_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); + if (is_guest_mode(vcpu)) { + vmx->nested.update_vmcs01_apicv_status = true; + return; + } + pin_controls_set(vmx, vmx_pin_based_exec_ctrl(vmx)); if (cpu_has_secondary_exec_ctrls()) { if (kvm_vcpu_apicv_active(vcpu)) diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 9c6bfcd84008..b98c7e96697a 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -183,6 +183,7 @@ struct nested_vmx { bool change_vmcs01_virtual_apic_mode; bool reload_vmcs01_apic_access_page; bool update_vmcs01_cpu_dirty_logging; + bool update_vmcs01_apicv_status; /* * Enlightened VMCS has been enabled. It does not mean that L1 has to

2 years, 8 months

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FAILED: patch "[PATCH] KVM: nVMX: Defer APICv updates while L2 is active until L1 is" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7c69661e225cc484fbf44a0b99b56714a5241ae3 Mon Sep 17 00:00:00 2001 From: Sean Christopherson <seanjc(a)google.com> Date: Wed, 20 Apr 2022 01:37:30 +0000 Subject: [PATCH] KVM: nVMX: Defer APICv updates while L2 is active until L1 is active Defer APICv updates that occur while L2 is active until nested VM-Exit, i.e. until L1 regains control. vmx_refresh_apicv_exec_ctrl() assumes L1 is active and (a) stomps all over vmcs02 and (b) neglects to ever updated vmcs01. E.g. if vmcs12 doesn't enable the TPR shadow for L2 (and thus no APICv controls), L1 performs nested VM-Enter APICv inhibited, and APICv becomes unhibited while L2 is active, KVM will set various APICv controls in vmcs02 and trigger a failed VM-Entry. The kicker is that, unless running with nested_early_check=1, KVM blames L1 and chaos ensues. In all cases, ignoring vmcs02 and always deferring the inhibition change to vmcs01 is correct (or at least acceptable). The ABSENT and DISABLE inhibitions cannot truly change while L2 is active (see below). IRQ_BLOCKING can change, but it is firmly a best effort debug feature. Furthermore, only L2's APIC is accelerated/virtualized to the full extent possible, e.g. even if L1 passes through its APIC to L2, normal MMIO/MSR interception will apply to the virtual APIC managed by KVM. The exception is the SELF_IPI register when x2APIC is enabled, but that's an acceptable hole. Lastly, Hyper-V's Auto EOI can technically be toggled if L1 exposes the MSRs to L2, but for that to work in any sane capacity, L1 would need to pass through IRQs to L2 as well, and IRQs must be intercepted to enable virtual interrupt delivery. I.e. exposing Auto EOI to L2 and enabling VID for L2 are, for all intents and purposes, mutually exclusive. Lack of dynamic toggling is also why this scenario is all but impossible to encounter in KVM's current form. But a future patch will pend an APICv update request _during_ vCPU creation to plug a race where a vCPU that's being created doesn't get included in the "all vCPUs request" because it's not yet visible to other vCPUs. If userspaces restores L2 after VM creation (hello, KVM selftests), the first KVM_RUN will occur while L2 is active and thus service the APICv update request made during VM creation. Cc: stable(a)vger.kernel.org Signed-off-by: Sean Christopherson <seanjc(a)google.com> Message-Id: <20220420013732.3308816-3-seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index f18744f7ff82..856c87563883 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -4618,6 +4618,11 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason, kvm_make_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu); } + if (vmx->nested.update_vmcs01_apicv_status) { + vmx->nested.update_vmcs01_apicv_status = false; + kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu); + } + if ((vm_exit_reason != -1) && (enable_shadow_vmcs || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))) vmx->nested.need_vmcs12_to_shadow_sync = true; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 04d170c4b61e..d58b763df855 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4174,6 +4174,11 @@ static void vmx_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); + if (is_guest_mode(vcpu)) { + vmx->nested.update_vmcs01_apicv_status = true; + return; + } + pin_controls_set(vmx, vmx_pin_based_exec_ctrl(vmx)); if (cpu_has_secondary_exec_ctrls()) { if (kvm_vcpu_apicv_active(vcpu)) diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 9c6bfcd84008..b98c7e96697a 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -183,6 +183,7 @@ struct nested_vmx { bool change_vmcs01_virtual_apic_mode; bool reload_vmcs01_apic_access_page; bool update_vmcs01_cpu_dirty_logging; + bool update_vmcs01_apicv_status; /* * Enlightened VMCS has been enabled. It does not mean that L1 has to

2 years, 8 months

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FAILED: patch "[PATCH] KVM: x86/pmu: Update AMD PMC sample period to fix guest" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 75189d1de1b377e580ebd2d2c55914631eac9c64 Mon Sep 17 00:00:00 2001 From: Like Xu <likexu(a)tencent.com> Date: Sat, 9 Apr 2022 09:52:26 +0800 Subject: [PATCH] KVM: x86/pmu: Update AMD PMC sample period to fix guest NMI-watchdog NMI-watchdog is one of the favorite features of kernel developers, but it does not work in AMD guest even with vPMU enabled and worse, the system misrepresents this capability via /proc. This is a PMC emulation error. KVM does not pass the latest valid value to perf_event in time when guest NMI-watchdog is running, thus the perf_event corresponding to the watchdog counter will enter the old state at some point after the first guest NMI injection, forcing the hardware register PMC0 to be constantly written to 0x800000000001. Meanwhile, the running counter should accurately reflect its new value based on the latest coordinated pmc->counter (from vPMC's point of view) rather than the value written directly by the guest. Fixes: 168d918f2643 ("KVM: x86: Adjust counter sample period after a wrmsr") Reported-by: Dongli Cao <caodongli(a)kingsoft.com> Signed-off-by: Like Xu <likexu(a)tencent.com> Reviewed-by: Yanan Wang <wangyanan55(a)huawei.com> Tested-by: Yanan Wang <wangyanan55(a)huawei.com> Reviewed-by: Jim Mattson <jmattson(a)google.com> Message-Id: <20220409015226.38619-1-likexu(a)tencent.com> Cc: stable(a)vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h index 9e66fba1d6a3..22992b049d38 100644 --- a/arch/x86/kvm/pmu.h +++ b/arch/x86/kvm/pmu.h @@ -138,6 +138,15 @@ static inline u64 get_sample_period(struct kvm_pmc *pmc, u64 counter_value) return sample_period; } +static inline void pmc_update_sample_period(struct kvm_pmc *pmc) +{ + if (!pmc->perf_event || pmc->is_paused) + return; + + perf_event_period(pmc->perf_event, + get_sample_period(pmc, pmc->counter)); +} + void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel); void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int fixed_idx); void reprogram_counter(struct kvm_pmu *pmu, int pmc_idx); diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c index 24eb935b6f85..b14860863c39 100644 --- a/arch/x86/kvm/svm/pmu.c +++ b/arch/x86/kvm/svm/pmu.c @@ -257,6 +257,7 @@ static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER); if (pmc) { pmc->counter += data - pmc_read_counter(pmc); + pmc_update_sample_period(pmc); return 0; } /* MSR_EVNTSELn */ diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index bc3f8512bb64..b82b6709d7a8 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -431,15 +431,11 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) !(msr & MSR_PMC_FULL_WIDTH_BIT)) data = (s64)(s32)data; pmc->counter += data - pmc_read_counter(pmc); - if (pmc->perf_event && !pmc->is_paused) - perf_event_period(pmc->perf_event, - get_sample_period(pmc, data)); + pmc_update_sample_period(pmc); return 0; } else if ((pmc = get_fixed_pmc(pmu, msr))) { pmc->counter += data - pmc_read_counter(pmc); - if (pmc->perf_event && !pmc->is_paused) - perf_event_period(pmc->perf_event, - get_sample_period(pmc, data)); + pmc_update_sample_period(pmc); return 0; } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) { if (data == pmc->eventsel)

2 years, 8 months

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[PATCH 5.10.y] drm/cirrus: fix a NULL vs IS_ERR() checks

by Shile Zhang

The function drm_gem_shmem_vmap can returns error pointers as well, which could cause following kernel crash: BUG: unable to handle page fault for address: fffffffffffffffc PGD 1426a12067 P4D 1426a12067 PUD 1426a14067 PMD 0 Oops: 0000 [#1] SMP NOPTI CPU: 12 PID: 3598532 Comm: stress-ng Kdump: loaded Not tainted 5.10.50.x86_64 #1 ... RIP: 0010:memcpy_toio+0x23/0x50 Code: 00 00 00 00 0f 1f 00 0f 1f 44 00 00 48 85 d2 74 28 40 f6 c7 01 75 2b 48 83 fa 01 76 06 40 f6 c7 02 75 17 48 89 d1 48 c1 e9 02 <f3> a5 f6 c2 02 74 02 66 a5 f6 c2 01 74 01 a4 c3 66 a5 48 83 ea 02 RSP: 0018:ffffafbf8a203c68 EFLAGS: 00010216 RAX: 0000000000000000 RBX: fffffffffffffffc RCX: 0000000000000200 RDX: 0000000000000800 RSI: fffffffffffffffc RDI: ffffafbf82000000 RBP: ffffafbf82000000 R08: 0000000000000002 R09: 0000000000000000 R10: 00000000000002b5 R11: 0000000000000000 R12: 0000000000000800 R13: ffff8a6801099300 R14: 0000000000000001 R15: 0000000000000300 FS: 00007f4a6bc5f740(0000) GS:ffff8a8641900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffffffffffffc CR3: 00000016d3874001 CR4: 00000000003606e0 Call Trace: drm_fb_memcpy_dstclip+0x5e/0x80 [drm_kms_helper] cirrus_fb_blit_rect.isra.0+0xb7/0xe0 [cirrus] cirrus_pipe_update+0x9f/0xa8 [cirrus] drm_atomic_helper_commit_planes+0xb8/0x220 [drm_kms_helper] drm_atomic_helper_commit_tail+0x42/0x80 [drm_kms_helper] commit_tail+0xce/0x130 [drm_kms_helper] drm_atomic_helper_commit+0x113/0x140 [drm_kms_helper] drm_client_modeset_commit_atomic+0x1c4/0x200 [drm] drm_client_modeset_commit_locked+0x53/0x80 [drm] drm_client_modeset_commit+0x24/0x40 [drm] drm_fbdev_client_restore+0x48/0x85 [drm_kms_helper] drm_client_dev_restore+0x64/0xb0 [drm] drm_release+0xf2/0x110 [drm] __fput+0x96/0x240 task_work_run+0x5c/0x90 exit_to_user_mode_loop+0xce/0xd0 exit_to_user_mode_prepare+0x6a/0x70 syscall_exit_to_user_mode+0x12/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f4a6bd82c2b Fixes: ab3e023b1b4c9 ("drm/cirrus: rewrite and modernize driver.") CC: stable(a)vger.kernel.org Reported-by: Wen Kang <kw01107137(a)alibaba-inc.com> Signed-off-by: Shile Zhang <shile.zhang(a)linux.alibaba.com> --- drivers/gpu/drm/tiny/cirrus.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/tiny/cirrus.c b/drivers/gpu/drm/tiny/cirrus.c index 744a8e337e41..d64f6bb767ee 100644 --- a/drivers/gpu/drm/tiny/cirrus.c +++ b/drivers/gpu/drm/tiny/cirrus.c @@ -323,7 +323,7 @@ static int cirrus_fb_blit_rect(struct drm_framebuffer *fb, ret = -ENOMEM; vmap = drm_gem_shmem_vmap(fb->obj[0]); - if (!vmap) + if (IS_ERR_OR_NULL(vmap)) goto out_dev_exit; if (cirrus->cpp == fb->format->cpp[0]) -- 2.33.0.rc2

2 years, 8 months

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FAILED: patch "[PATCH] ASoC: rt5682: fix an incorrect NULL check on list iterator" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From c8618d65007ba68d7891130642d73e89372101e8 Mon Sep 17 00:00:00 2001 From: Xiaomeng Tong <xiam0nd.tong(a)gmail.com> Date: Sun, 27 Mar 2022 16:10:02 +0800 Subject: [PATCH] ASoC: rt5682: fix an incorrect NULL check on list iterator The bug is here: if (!dai) { The list iterator value 'dai' will *always* be set and non-NULL by for_each_component_dais(), so it is incorrect to assume that the iterator value will be NULL if the list is empty or no element is found (In fact, it will be a bogus pointer to an invalid struct object containing the HEAD). Otherwise it will bypass the check 'if (!dai) {' (never call dev_err() and never return -ENODEV;) and lead to invalid memory access lately when calling 'rt5682_set_bclk1_ratio(dai, factor);'. To fix the bug, just return rt5682_set_bclk1_ratio(dai, factor); when found the 'dai', otherwise dev_err() and return -ENODEV; Cc: stable(a)vger.kernel.org Fixes: ebbfabc16d23d ("ASoC: rt5682: Add CCF usage for providing I2S clks") Signed-off-by: Xiaomeng Tong <xiam0nd.tong(a)gmail.com> Link: https://lore.kernel.org/r/20220327081002.12684-1-xiam0nd.tong@gmail.com Signed-off-by: Mark Brown <broonie(a)kernel.org> diff --git a/sound/soc/codecs/rt5682.c b/sound/soc/codecs/rt5682.c index be68d573a490..c9ff9c89adf7 100644 --- a/sound/soc/codecs/rt5682.c +++ b/sound/soc/codecs/rt5682.c @@ -2822,14 +2822,11 @@ static int rt5682_bclk_set_rate(struct clk_hw *hw, unsigned long rate, for_each_component_dais(component, dai) if (dai->id == RT5682_AIF1) - break; - if (!dai) { - dev_err(rt5682->i2c_dev, "dai %d not found in component\n", - RT5682_AIF1); - return -ENODEV; - } + return rt5682_set_bclk1_ratio(dai, factor); - return rt5682_set_bclk1_ratio(dai, factor); + dev_err(rt5682->i2c_dev, "dai %d not found in component\n", + RT5682_AIF1); + return -ENODEV; } static const struct clk_ops rt5682_dai_clk_ops[RT5682_DAI_NUM_CLKS] = {

2 years, 8 months

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FAILED: patch "[PATCH] ASoC: rt5682: fix an incorrect NULL check on list iterator" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From c8618d65007ba68d7891130642d73e89372101e8 Mon Sep 17 00:00:00 2001 From: Xiaomeng Tong <xiam0nd.tong(a)gmail.com> Date: Sun, 27 Mar 2022 16:10:02 +0800 Subject: [PATCH] ASoC: rt5682: fix an incorrect NULL check on list iterator The bug is here: if (!dai) { The list iterator value 'dai' will *always* be set and non-NULL by for_each_component_dais(), so it is incorrect to assume that the iterator value will be NULL if the list is empty or no element is found (In fact, it will be a bogus pointer to an invalid struct object containing the HEAD). Otherwise it will bypass the check 'if (!dai) {' (never call dev_err() and never return -ENODEV;) and lead to invalid memory access lately when calling 'rt5682_set_bclk1_ratio(dai, factor);'. To fix the bug, just return rt5682_set_bclk1_ratio(dai, factor); when found the 'dai', otherwise dev_err() and return -ENODEV; Cc: stable(a)vger.kernel.org Fixes: ebbfabc16d23d ("ASoC: rt5682: Add CCF usage for providing I2S clks") Signed-off-by: Xiaomeng Tong <xiam0nd.tong(a)gmail.com> Link: https://lore.kernel.org/r/20220327081002.12684-1-xiam0nd.tong@gmail.com Signed-off-by: Mark Brown <broonie(a)kernel.org> diff --git a/sound/soc/codecs/rt5682.c b/sound/soc/codecs/rt5682.c index be68d573a490..c9ff9c89adf7 100644 --- a/sound/soc/codecs/rt5682.c +++ b/sound/soc/codecs/rt5682.c @@ -2822,14 +2822,11 @@ static int rt5682_bclk_set_rate(struct clk_hw *hw, unsigned long rate, for_each_component_dais(component, dai) if (dai->id == RT5682_AIF1) - break; - if (!dai) { - dev_err(rt5682->i2c_dev, "dai %d not found in component\n", - RT5682_AIF1); - return -ENODEV; - } + return rt5682_set_bclk1_ratio(dai, factor); - return rt5682_set_bclk1_ratio(dai, factor); + dev_err(rt5682->i2c_dev, "dai %d not found in component\n", + RT5682_AIF1); + return -ENODEV; } static const struct clk_ops rt5682_dai_clk_ops[RT5682_DAI_NUM_CLKS] = {

2 years, 8 months

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FAILED: patch "[PATCH] xtensa: fix a7 clobbering in coprocessor context load/store" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 839769c35477d4acc2369e45000ca7b0b6af39a7 Mon Sep 17 00:00:00 2001 From: Max Filippov <jcmvbkbc(a)gmail.com> Date: Wed, 13 Apr 2022 22:44:36 -0700 Subject: [PATCH] xtensa: fix a7 clobbering in coprocessor context load/store Fast coprocessor exception handler saves a3..a6, but coprocessor context load/store code uses a4..a7 as temporaries, potentially clobbering a7. 'Potentially' because coprocessor state load/store macros may not use all four temporary registers (and neither FPU nor HiFi macros do). Use a3..a6 as intended. Cc: stable(a)vger.kernel.org Fixes: c658eac628aa ("[XTENSA] Add support for configurable registers and coprocessors") Signed-off-by: Max Filippov <jcmvbkbc(a)gmail.com> diff --git a/arch/xtensa/kernel/coprocessor.S b/arch/xtensa/kernel/coprocessor.S index 45cc0ae0af6f..c7b9f12896f2 100644 --- a/arch/xtensa/kernel/coprocessor.S +++ b/arch/xtensa/kernel/coprocessor.S @@ -29,7 +29,7 @@ .if XTENSA_HAVE_COPROCESSOR(x); \ .align 4; \ .Lsave_cp_regs_cp##x: \ - xchal_cp##x##_store a2 a4 a5 a6 a7; \ + xchal_cp##x##_store a2 a3 a4 a5 a6; \ jx a0; \ .endif @@ -46,7 +46,7 @@ .if XTENSA_HAVE_COPROCESSOR(x); \ .align 4; \ .Lload_cp_regs_cp##x: \ - xchal_cp##x##_load a2 a4 a5 a6 a7; \ + xchal_cp##x##_load a2 a3 a4 a5 a6; \ jx a0; \ .endif

2 years, 8 months

1
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