June 2024 - Linux-stable-mirror

FAILED: patch "[PATCH] KVM: arm64: Disassociate vcpus from redistributor region on" 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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 0d92e4a7ffd5c42b9fa864692f82476c0bf8bcc8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024062438-dean-sacrifice-9c3b@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0d92e4a7ffd5c42b9fa864692f82476c0bf8bcc8 Mon Sep 17 00:00:00 2001 From: Marc Zyngier <maz(a)kernel.org> Date: Wed, 5 Jun 2024 18:56:37 +0100 Subject: [PATCH] KVM: arm64: Disassociate vcpus from redistributor region on teardown When tearing down a redistributor region, make sure we don't have any dangling pointer to that region stored in a vcpu. Fixes: e5a35635464b ("kvm: arm64: vgic-v3: Introduce vgic_v3_free_redist_region()") Reported-by: Alexander Potapenko <glider(a)google.com> Reviewed-by: Oliver Upton <oliver.upton(a)linux.dev> Signed-off-by: Marc Zyngier <maz(a)kernel.org> Link: https://lore.kernel.org/r/20240605175637.1635653-1-maz@kernel.org Cc: stable(a)vger.kernel.org diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c index 8f5b7a3e7009..7f68cf58b978 100644 --- a/arch/arm64/kvm/vgic/vgic-init.c +++ b/arch/arm64/kvm/vgic/vgic-init.c @@ -391,7 +391,7 @@ static void kvm_vgic_dist_destroy(struct kvm *kvm) if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) { list_for_each_entry_safe(rdreg, next, &dist->rd_regions, list) - vgic_v3_free_redist_region(rdreg); + vgic_v3_free_redist_region(kvm, rdreg); INIT_LIST_HEAD(&dist->rd_regions); } else { dist->vgic_cpu_base = VGIC_ADDR_UNDEF; diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c index a3983a631b5a..9e50928f5d7d 100644 --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c @@ -919,8 +919,19 @@ static int vgic_v3_alloc_redist_region(struct kvm *kvm, uint32_t index, return ret; } -void vgic_v3_free_redist_region(struct vgic_redist_region *rdreg) +void vgic_v3_free_redist_region(struct kvm *kvm, struct vgic_redist_region *rdreg) { + struct kvm_vcpu *vcpu; + unsigned long c; + + lockdep_assert_held(&kvm->arch.config_lock); + + /* Garbage collect the region */ + kvm_for_each_vcpu(c, vcpu, kvm) { + if (vcpu->arch.vgic_cpu.rdreg == rdreg) + vcpu->arch.vgic_cpu.rdreg = NULL; + } + list_del(&rdreg->list); kfree(rdreg); } @@ -945,7 +956,7 @@ int vgic_v3_set_redist_base(struct kvm *kvm, u32 index, u64 addr, u32 count) mutex_lock(&kvm->arch.config_lock); rdreg = vgic_v3_rdist_region_from_index(kvm, index); - vgic_v3_free_redist_region(rdreg); + vgic_v3_free_redist_region(kvm, rdreg); mutex_unlock(&kvm->arch.config_lock); return ret; } diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h index 6106ebd5ba42..03d356a12377 100644 --- a/arch/arm64/kvm/vgic/vgic.h +++ b/arch/arm64/kvm/vgic/vgic.h @@ -316,7 +316,7 @@ vgic_v3_rd_region_size(struct kvm *kvm, struct vgic_redist_region *rdreg) struct vgic_redist_region *vgic_v3_rdist_region_from_index(struct kvm *kvm, u32 index); -void vgic_v3_free_redist_region(struct vgic_redist_region *rdreg); +void vgic_v3_free_redist_region(struct kvm *kvm, struct vgic_redist_region *rdreg); bool vgic_v3_rdist_overlap(struct kvm *kvm, gpa_t base, size_t size);

6 months, 1 week

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FAILED: patch "[PATCH] KVM: Fix a data race on last_boosted_vcpu in" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x 49f683b41f28918df3e51ddc0d928cb2e934ccdb # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024062422-composer-engaging-202c@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 49f683b41f28918df3e51ddc0d928cb2e934ccdb Mon Sep 17 00:00:00 2001 From: Breno Leitao <leitao(a)debian.org> Date: Fri, 10 May 2024 02:23:52 -0700 Subject: [PATCH] KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() Use {READ,WRITE}_ONCE() to access kvm->last_boosted_vcpu to ensure the loads and stores are atomic. In the extremely unlikely scenario the compiler tears the stores, it's theoretically possible for KVM to attempt to get a vCPU using an out-of-bounds index, e.g. if the write is split into multiple 8-bit stores, and is paired with a 32-bit load on a VM with 257 vCPUs: CPU0 CPU1 last_boosted_vcpu = 0xff; (last_boosted_vcpu = 0x100) last_boosted_vcpu[15:8] = 0x01; i = (last_boosted_vcpu = 0x1ff) last_boosted_vcpu[7:0] = 0x00; vcpu = kvm->vcpu_array[0x1ff]; As detected by KCSAN: BUG: KCSAN: data-race in kvm_vcpu_on_spin [kvm] / kvm_vcpu_on_spin [kvm] write to 0xffffc90025a92344 of 4 bytes by task 4340 on cpu 16: kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4112) kvm handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:? arch/x86/kvm/vmx/vmx.c:6606) kvm_intel vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm __se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890) __x64_sys_ioctl (fs/ioctl.c:890) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) read to 0xffffc90025a92344 of 4 bytes by task 4342 on cpu 4: kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4069) kvm handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:? arch/x86/kvm/vmx/vmx.c:6606) kvm_intel vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm __se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890) __x64_sys_ioctl (fs/ioctl.c:890) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) value changed: 0x00000012 -> 0x00000000 Fixes: 217ece6129f2 ("KVM: use yield_to instead of sleep in kvm_vcpu_on_spin") Cc: stable(a)vger.kernel.org Signed-off-by: Breno Leitao <leitao(a)debian.org> Link: https://lore.kernel.org/r/20240510092353.2261824-1-leitao@debian.org Signed-off-by: Sean Christopherson <seanjc(a)google.com> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 14841acb8b95..843aa68cbcd0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4025,12 +4025,13 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) { struct kvm *kvm = me->kvm; struct kvm_vcpu *vcpu; - int last_boosted_vcpu = me->kvm->last_boosted_vcpu; + int last_boosted_vcpu; unsigned long i; int yielded = 0; int try = 3; int pass; + last_boosted_vcpu = READ_ONCE(kvm->last_boosted_vcpu); kvm_vcpu_set_in_spin_loop(me, true); /* * We boost the priority of a VCPU that is runnable but not @@ -4068,7 +4069,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) yielded = kvm_vcpu_yield_to(vcpu); if (yielded > 0) { - kvm->last_boosted_vcpu = i; + WRITE_ONCE(kvm->last_boosted_vcpu, i); break; } else if (yielded < 0) { try--;

6 months, 1 week

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FAILED: patch "[PATCH] KVM: Fix a data race on last_boosted_vcpu in" 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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 49f683b41f28918df3e51ddc0d928cb2e934ccdb # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024062420-pendant-avenging-0263@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 49f683b41f28918df3e51ddc0d928cb2e934ccdb Mon Sep 17 00:00:00 2001 From: Breno Leitao <leitao(a)debian.org> Date: Fri, 10 May 2024 02:23:52 -0700 Subject: [PATCH] KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() Use {READ,WRITE}_ONCE() to access kvm->last_boosted_vcpu to ensure the loads and stores are atomic. In the extremely unlikely scenario the compiler tears the stores, it's theoretically possible for KVM to attempt to get a vCPU using an out-of-bounds index, e.g. if the write is split into multiple 8-bit stores, and is paired with a 32-bit load on a VM with 257 vCPUs: CPU0 CPU1 last_boosted_vcpu = 0xff; (last_boosted_vcpu = 0x100) last_boosted_vcpu[15:8] = 0x01; i = (last_boosted_vcpu = 0x1ff) last_boosted_vcpu[7:0] = 0x00; vcpu = kvm->vcpu_array[0x1ff]; As detected by KCSAN: BUG: KCSAN: data-race in kvm_vcpu_on_spin [kvm] / kvm_vcpu_on_spin [kvm] write to 0xffffc90025a92344 of 4 bytes by task 4340 on cpu 16: kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4112) kvm handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:? arch/x86/kvm/vmx/vmx.c:6606) kvm_intel vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm __se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890) __x64_sys_ioctl (fs/ioctl.c:890) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) read to 0xffffc90025a92344 of 4 bytes by task 4342 on cpu 4: kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4069) kvm handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:? arch/x86/kvm/vmx/vmx.c:6606) kvm_intel vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm __se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890) __x64_sys_ioctl (fs/ioctl.c:890) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) value changed: 0x00000012 -> 0x00000000 Fixes: 217ece6129f2 ("KVM: use yield_to instead of sleep in kvm_vcpu_on_spin") Cc: stable(a)vger.kernel.org Signed-off-by: Breno Leitao <leitao(a)debian.org> Link: https://lore.kernel.org/r/20240510092353.2261824-1-leitao@debian.org Signed-off-by: Sean Christopherson <seanjc(a)google.com> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 14841acb8b95..843aa68cbcd0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4025,12 +4025,13 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) { struct kvm *kvm = me->kvm; struct kvm_vcpu *vcpu; - int last_boosted_vcpu = me->kvm->last_boosted_vcpu; + int last_boosted_vcpu; unsigned long i; int yielded = 0; int try = 3; int pass; + last_boosted_vcpu = READ_ONCE(kvm->last_boosted_vcpu); kvm_vcpu_set_in_spin_loop(me, true); /* * We boost the priority of a VCPU that is runnable but not @@ -4068,7 +4069,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) yielded = kvm_vcpu_yield_to(vcpu); if (yielded > 0) { - kvm->last_boosted_vcpu = i; + WRITE_ONCE(kvm->last_boosted_vcpu, i); break; } else if (yielded < 0) { try--;

6 months, 1 week

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FAILED: patch "[PATCH] KVM: Fix a data race on last_boosted_vcpu in" 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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 49f683b41f28918df3e51ddc0d928cb2e934ccdb # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024062419-goes-tingling-5681@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 49f683b41f28918df3e51ddc0d928cb2e934ccdb Mon Sep 17 00:00:00 2001 From: Breno Leitao <leitao(a)debian.org> Date: Fri, 10 May 2024 02:23:52 -0700 Subject: [PATCH] KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() Use {READ,WRITE}_ONCE() to access kvm->last_boosted_vcpu to ensure the loads and stores are atomic. In the extremely unlikely scenario the compiler tears the stores, it's theoretically possible for KVM to attempt to get a vCPU using an out-of-bounds index, e.g. if the write is split into multiple 8-bit stores, and is paired with a 32-bit load on a VM with 257 vCPUs: CPU0 CPU1 last_boosted_vcpu = 0xff; (last_boosted_vcpu = 0x100) last_boosted_vcpu[15:8] = 0x01; i = (last_boosted_vcpu = 0x1ff) last_boosted_vcpu[7:0] = 0x00; vcpu = kvm->vcpu_array[0x1ff]; As detected by KCSAN: BUG: KCSAN: data-race in kvm_vcpu_on_spin [kvm] / kvm_vcpu_on_spin [kvm] write to 0xffffc90025a92344 of 4 bytes by task 4340 on cpu 16: kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4112) kvm handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:? arch/x86/kvm/vmx/vmx.c:6606) kvm_intel vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm __se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890) __x64_sys_ioctl (fs/ioctl.c:890) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) read to 0xffffc90025a92344 of 4 bytes by task 4342 on cpu 4: kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4069) kvm handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:? arch/x86/kvm/vmx/vmx.c:6606) kvm_intel vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm __se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890) __x64_sys_ioctl (fs/ioctl.c:890) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) value changed: 0x00000012 -> 0x00000000 Fixes: 217ece6129f2 ("KVM: use yield_to instead of sleep in kvm_vcpu_on_spin") Cc: stable(a)vger.kernel.org Signed-off-by: Breno Leitao <leitao(a)debian.org> Link: https://lore.kernel.org/r/20240510092353.2261824-1-leitao@debian.org Signed-off-by: Sean Christopherson <seanjc(a)google.com> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 14841acb8b95..843aa68cbcd0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4025,12 +4025,13 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) { struct kvm *kvm = me->kvm; struct kvm_vcpu *vcpu; - int last_boosted_vcpu = me->kvm->last_boosted_vcpu; + int last_boosted_vcpu; unsigned long i; int yielded = 0; int try = 3; int pass; + last_boosted_vcpu = READ_ONCE(kvm->last_boosted_vcpu); kvm_vcpu_set_in_spin_loop(me, true); /* * We boost the priority of a VCPU that is runnable but not @@ -4068,7 +4069,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) yielded = kvm_vcpu_yield_to(vcpu); if (yielded > 0) { - kvm->last_boosted_vcpu = i; + WRITE_ONCE(kvm->last_boosted_vcpu, i); break; } else if (yielded < 0) { try--;

6 months, 1 week

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FAILED: patch "[PATCH] KVM: Fix a data race on last_boosted_vcpu in" 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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 49f683b41f28918df3e51ddc0d928cb2e934ccdb # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024062418-emboss-transpose-5310@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 49f683b41f28918df3e51ddc0d928cb2e934ccdb Mon Sep 17 00:00:00 2001 From: Breno Leitao <leitao(a)debian.org> Date: Fri, 10 May 2024 02:23:52 -0700 Subject: [PATCH] KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() Use {READ,WRITE}_ONCE() to access kvm->last_boosted_vcpu to ensure the loads and stores are atomic. In the extremely unlikely scenario the compiler tears the stores, it's theoretically possible for KVM to attempt to get a vCPU using an out-of-bounds index, e.g. if the write is split into multiple 8-bit stores, and is paired with a 32-bit load on a VM with 257 vCPUs: CPU0 CPU1 last_boosted_vcpu = 0xff; (last_boosted_vcpu = 0x100) last_boosted_vcpu[15:8] = 0x01; i = (last_boosted_vcpu = 0x1ff) last_boosted_vcpu[7:0] = 0x00; vcpu = kvm->vcpu_array[0x1ff]; As detected by KCSAN: BUG: KCSAN: data-race in kvm_vcpu_on_spin [kvm] / kvm_vcpu_on_spin [kvm] write to 0xffffc90025a92344 of 4 bytes by task 4340 on cpu 16: kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4112) kvm handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:? arch/x86/kvm/vmx/vmx.c:6606) kvm_intel vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm __se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890) __x64_sys_ioctl (fs/ioctl.c:890) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) read to 0xffffc90025a92344 of 4 bytes by task 4342 on cpu 4: kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4069) kvm handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:? arch/x86/kvm/vmx/vmx.c:6606) kvm_intel vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm __se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890) __x64_sys_ioctl (fs/ioctl.c:890) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) value changed: 0x00000012 -> 0x00000000 Fixes: 217ece6129f2 ("KVM: use yield_to instead of sleep in kvm_vcpu_on_spin") Cc: stable(a)vger.kernel.org Signed-off-by: Breno Leitao <leitao(a)debian.org> Link: https://lore.kernel.org/r/20240510092353.2261824-1-leitao@debian.org Signed-off-by: Sean Christopherson <seanjc(a)google.com> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 14841acb8b95..843aa68cbcd0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4025,12 +4025,13 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) { struct kvm *kvm = me->kvm; struct kvm_vcpu *vcpu; - int last_boosted_vcpu = me->kvm->last_boosted_vcpu; + int last_boosted_vcpu; unsigned long i; int yielded = 0; int try = 3; int pass; + last_boosted_vcpu = READ_ONCE(kvm->last_boosted_vcpu); kvm_vcpu_set_in_spin_loop(me, true); /* * We boost the priority of a VCPU that is runnable but not @@ -4068,7 +4069,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) yielded = kvm_vcpu_yield_to(vcpu); if (yielded > 0) { - kvm->last_boosted_vcpu = i; + WRITE_ONCE(kvm->last_boosted_vcpu, i); break; } else if (yielded < 0) { try--;

6 months, 1 week

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FAILED: patch "[PATCH] LoongArch: KVM: Remove an unneeded semicolon" failed to apply to 6.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.9-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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.9.y git checkout FETCH_HEAD git cherry-pick -x d0a1c07739e1b7f74683fe061545669156d102f2 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024062451-unsalted-unvalued-9498@gregkh' --subject-prefix 'PATCH 6.9.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From d0a1c07739e1b7f74683fe061545669156d102f2 Mon Sep 17 00:00:00 2001 From: Yang Li <yang.lee(a)linux.alibaba.com> Date: Fri, 21 Jun 2024 10:18:40 +0800 Subject: [PATCH] LoongArch: KVM: Remove an unneeded semicolon Remove an unneeded semicolon to avoid build warnings: ./arch/loongarch/kvm/exit.c:764:2-3: Unneeded semicolon Cc: stable(a)vger.kernel.org Reported-by: Abaci Robot <abaci(a)linux.alibaba.com> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9343 Signed-off-by: Yang Li <yang.lee(a)linux.alibaba.com> Signed-off-by: Huacai Chen <chenhuacai(a)loongson.cn> diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c index c86e099af5ca..a68573e091c0 100644 --- a/arch/loongarch/kvm/exit.c +++ b/arch/loongarch/kvm/exit.c @@ -761,7 +761,7 @@ static void kvm_handle_service(struct kvm_vcpu *vcpu) default: ret = KVM_HCALL_INVALID_CODE; break; - }; + } kvm_write_reg(vcpu, LOONGARCH_GPR_A0, ret); }

6 months, 1 week

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FAILED: patch "[PATCH] LoongArch: KVM: Remove an unneeded semicolon" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x d0a1c07739e1b7f74683fe061545669156d102f2 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024062452-savage-commotion-3ab2@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From d0a1c07739e1b7f74683fe061545669156d102f2 Mon Sep 17 00:00:00 2001 From: Yang Li <yang.lee(a)linux.alibaba.com> Date: Fri, 21 Jun 2024 10:18:40 +0800 Subject: [PATCH] LoongArch: KVM: Remove an unneeded semicolon Remove an unneeded semicolon to avoid build warnings: ./arch/loongarch/kvm/exit.c:764:2-3: Unneeded semicolon Cc: stable(a)vger.kernel.org Reported-by: Abaci Robot <abaci(a)linux.alibaba.com> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9343 Signed-off-by: Yang Li <yang.lee(a)linux.alibaba.com> Signed-off-by: Huacai Chen <chenhuacai(a)loongson.cn> diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c index c86e099af5ca..a68573e091c0 100644 --- a/arch/loongarch/kvm/exit.c +++ b/arch/loongarch/kvm/exit.c @@ -761,7 +761,7 @@ static void kvm_handle_service(struct kvm_vcpu *vcpu) default: ret = KVM_HCALL_INVALID_CODE; break; - }; + } kvm_write_reg(vcpu, LOONGARCH_GPR_A0, ret); }

6 months, 1 week

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FAILED: patch "[PATCH] cifs: drop the incorrect assertion in cifs_swap_rw()" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 29433a17a79caa8680b9c0761f2b10502fda9ce3 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024062429-swinging-gully-4fc8@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 29433a17a79caa8680b9c0761f2b10502fda9ce3 Mon Sep 17 00:00:00 2001 From: Barry Song <baohua(a)kernel.org> Date: Tue, 18 Jun 2024 19:22:58 +1200 Subject: [PATCH] cifs: drop the incorrect assertion in cifs_swap_rw() Since commit 2282679fb20b ("mm: submit multipage write for SWP_FS_OPS swap-space"), we can plug multiple pages then unplug them all together. That means iov_iter_count(iter) could be way bigger than PAGE_SIZE, it actually equals the size of iov_iter_npages(iter, INT_MAX). Note this issue has nothing to do with large folios as we don't support THP_SWPOUT to non-block devices. Fixes: 2282679fb20b ("mm: submit multipage write for SWP_FS_OPS swap-space") Reported-by: Christoph Hellwig <hch(a)lst.de> Closes: https://lore.kernel.org/linux-mm/20240614100329.1203579-1-hch@lst.de/ Cc: NeilBrown <neilb(a)suse.de> Cc: Anna Schumaker <anna(a)kernel.org> Cc: Steve French <sfrench(a)samba.org> Cc: Trond Myklebust <trondmy(a)kernel.org> Cc: Chuanhua Han <hanchuanhua(a)oppo.com> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Chris Li <chrisl(a)kernel.org> Cc: "Huang, Ying" <ying.huang(a)intel.com> Cc: Jeff Layton <jlayton(a)kernel.org> Cc: Paulo Alcantara <pc(a)manguebit.com> Cc: Ronnie Sahlberg <ronniesahlberg(a)gmail.com> Cc: Shyam Prasad N <sprasad(a)microsoft.com> Cc: Tom Talpey <tom(a)talpey.com> Cc: Bharath SM <bharathsm(a)microsoft.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Barry Song <v-songbaohua(a)oppo.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c index 9d5c2440abfc..1e269e0bc75b 100644 --- a/fs/smb/client/file.c +++ b/fs/smb/client/file.c @@ -3200,8 +3200,6 @@ static int cifs_swap_rw(struct kiocb *iocb, struct iov_iter *iter) { ssize_t ret; - WARN_ON_ONCE(iov_iter_count(iter) != PAGE_SIZE); - if (iov_iter_rw(iter) == READ) ret = netfs_unbuffered_read_iter_locked(iocb, iter); else

6 months, 1 week

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FAILED: patch "[PATCH] cifs: drop the incorrect assertion in cifs_swap_rw()" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 29433a17a79caa8680b9c0761f2b10502fda9ce3 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024062428-juggle-shrine-cd22@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 29433a17a79caa8680b9c0761f2b10502fda9ce3 Mon Sep 17 00:00:00 2001 From: Barry Song <baohua(a)kernel.org> Date: Tue, 18 Jun 2024 19:22:58 +1200 Subject: [PATCH] cifs: drop the incorrect assertion in cifs_swap_rw() Since commit 2282679fb20b ("mm: submit multipage write for SWP_FS_OPS swap-space"), we can plug multiple pages then unplug them all together. That means iov_iter_count(iter) could be way bigger than PAGE_SIZE, it actually equals the size of iov_iter_npages(iter, INT_MAX). Note this issue has nothing to do with large folios as we don't support THP_SWPOUT to non-block devices. Fixes: 2282679fb20b ("mm: submit multipage write for SWP_FS_OPS swap-space") Reported-by: Christoph Hellwig <hch(a)lst.de> Closes: https://lore.kernel.org/linux-mm/20240614100329.1203579-1-hch@lst.de/ Cc: NeilBrown <neilb(a)suse.de> Cc: Anna Schumaker <anna(a)kernel.org> Cc: Steve French <sfrench(a)samba.org> Cc: Trond Myklebust <trondmy(a)kernel.org> Cc: Chuanhua Han <hanchuanhua(a)oppo.com> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Chris Li <chrisl(a)kernel.org> Cc: "Huang, Ying" <ying.huang(a)intel.com> Cc: Jeff Layton <jlayton(a)kernel.org> Cc: Paulo Alcantara <pc(a)manguebit.com> Cc: Ronnie Sahlberg <ronniesahlberg(a)gmail.com> Cc: Shyam Prasad N <sprasad(a)microsoft.com> Cc: Tom Talpey <tom(a)talpey.com> Cc: Bharath SM <bharathsm(a)microsoft.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Barry Song <v-songbaohua(a)oppo.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c index 9d5c2440abfc..1e269e0bc75b 100644 --- a/fs/smb/client/file.c +++ b/fs/smb/client/file.c @@ -3200,8 +3200,6 @@ static int cifs_swap_rw(struct kiocb *iocb, struct iov_iter *iter) { ssize_t ret; - WARN_ON_ONCE(iov_iter_count(iter) != PAGE_SIZE); - if (iov_iter_rw(iter) == READ) ret = netfs_unbuffered_read_iter_locked(iocb, iter); else

6 months, 1 week

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FAILED: patch "[PATCH] cifs: drop the incorrect assertion in cifs_swap_rw()" failed to apply to 6.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.9-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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.9.y git checkout FETCH_HEAD git cherry-pick -x 29433a17a79caa8680b9c0761f2b10502fda9ce3 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024062428-captivate-grasp-a4cf@gregkh' --subject-prefix 'PATCH 6.9.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 29433a17a79caa8680b9c0761f2b10502fda9ce3 Mon Sep 17 00:00:00 2001 From: Barry Song <baohua(a)kernel.org> Date: Tue, 18 Jun 2024 19:22:58 +1200 Subject: [PATCH] cifs: drop the incorrect assertion in cifs_swap_rw() Since commit 2282679fb20b ("mm: submit multipage write for SWP_FS_OPS swap-space"), we can plug multiple pages then unplug them all together. That means iov_iter_count(iter) could be way bigger than PAGE_SIZE, it actually equals the size of iov_iter_npages(iter, INT_MAX). Note this issue has nothing to do with large folios as we don't support THP_SWPOUT to non-block devices. Fixes: 2282679fb20b ("mm: submit multipage write for SWP_FS_OPS swap-space") Reported-by: Christoph Hellwig <hch(a)lst.de> Closes: https://lore.kernel.org/linux-mm/20240614100329.1203579-1-hch@lst.de/ Cc: NeilBrown <neilb(a)suse.de> Cc: Anna Schumaker <anna(a)kernel.org> Cc: Steve French <sfrench(a)samba.org> Cc: Trond Myklebust <trondmy(a)kernel.org> Cc: Chuanhua Han <hanchuanhua(a)oppo.com> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Chris Li <chrisl(a)kernel.org> Cc: "Huang, Ying" <ying.huang(a)intel.com> Cc: Jeff Layton <jlayton(a)kernel.org> Cc: Paulo Alcantara <pc(a)manguebit.com> Cc: Ronnie Sahlberg <ronniesahlberg(a)gmail.com> Cc: Shyam Prasad N <sprasad(a)microsoft.com> Cc: Tom Talpey <tom(a)talpey.com> Cc: Bharath SM <bharathsm(a)microsoft.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Barry Song <v-songbaohua(a)oppo.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c index 9d5c2440abfc..1e269e0bc75b 100644 --- a/fs/smb/client/file.c +++ b/fs/smb/client/file.c @@ -3200,8 +3200,6 @@ static int cifs_swap_rw(struct kiocb *iocb, struct iov_iter *iter) { ssize_t ret; - WARN_ON_ONCE(iov_iter_count(iter) != PAGE_SIZE); - if (iov_iter_rw(iter) == READ) ret = netfs_unbuffered_read_iter_locked(iocb, iter); else

6 months, 1 week

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