Re: [PATCH 5.15.y 1/3] KVM: arm64: vgic-its: Add a data length check in vgic_its_save_*

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: 7fe28d7e68f92cc3d0668b8f2fbdf5c303ac3022


Status in newer kernel trees:
6.12.y | Not found
6.11.y | Not found
6.6.y | Not found
6.1.y | Not found
5.15.y | Not found

Note: The patch differs from the upstream commit:
---
1:  7fe28d7e68f92 ! 1:  e7bc6980df78e KVM: arm64: vgic-its: Add a data length check in vgic_its_save_*
    @@ Metadata
      ## Commit message ##
         KVM: arm64: vgic-its: Add a data length check in vgic_its_save_*
     
    +    commit 7fe28d7e68f92cc3d0668b8f2fbdf5c303ac3022 upstream.
    +
         In all the vgic_its_save_*() functinos, they do not check whether
         the data length is 8 bytes before calling vgic_write_guest_lock.
         This patch adds the check. To prevent the kernel from being blown up
    @@ arch/arm64/kvm/vgic/vgic-its.c: static int vgic_its_save_ite(struct vgic_its *it
      	       ((u64)ite->irq->intid << KVM_ITS_ITE_PINTID_SHIFT) |
      		ite->collection->collection_id;
      	val = cpu_to_le64(val);
    --	return vgic_write_guest_lock(kvm, gpa, &val, ite_esz);
    +-	return kvm_write_guest_lock(kvm, gpa, &val, ite_esz);
     +
     +	return vgic_its_write_entry_lock(its, gpa, val, ite_esz);
      }
    @@ arch/arm64/kvm/vgic/vgic-its.c: static int vgic_its_save_dte(struct vgic_its *it
      	       (itt_addr_field << KVM_ITS_DTE_ITTADDR_SHIFT) |
      		(dev->num_eventid_bits - 1));
      	val = cpu_to_le64(val);
    --	return vgic_write_guest_lock(kvm, ptr, &val, dte_esz);
    +-	return kvm_write_guest_lock(kvm, ptr, &val, dte_esz);
     +
     +	return vgic_its_write_entry_lock(its, ptr, val, dte_esz);
      }
    @@ arch/arm64/kvm/vgic/vgic-its.c: static int vgic_its_save_cte(struct vgic_its *it
      	       ((u64)collection->target_addr << KVM_ITS_CTE_RDBASE_SHIFT) |
      	       collection->collection_id);
      	val = cpu_to_le64(val);
    --	return vgic_write_guest_lock(its->dev->kvm, gpa, &val, esz);
    +-	return kvm_write_guest_lock(its->dev->kvm, gpa, &val, esz);
     +
     +	return vgic_its_write_entry_lock(its, gpa, val, esz);
      }
      
    - /*
    + static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz)
     @@ arch/arm64/kvm/vgic/vgic-its.c: static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz)
      	u64 val;
      	int ret;
    @@ arch/arm64/kvm/vgic/vgic-its.c: static int vgic_its_save_collection_table(struct
      	 */
     -	val = 0;
     -	BUG_ON(cte_esz > sizeof(val));
    --	ret = vgic_write_guest_lock(its->dev->kvm, gpa, &val, cte_esz);
    +-	ret = kvm_write_guest_lock(its->dev->kvm, gpa, &val, cte_esz);
     -	return ret;
     +	return vgic_its_write_entry_lock(its, gpa, 0, cte_esz);
      }
      
    - /*
    + /**
     
      ## arch/arm64/kvm/vgic/vgic.h ##
    -@@ arch/arm64/kvm/vgic/vgic.h: static inline int vgic_write_guest_lock(struct kvm *kvm, gpa_t gpa,
    - 	return ret;
    +@@
    + #define __KVM_ARM_VGIC_NEW_H__
    + 
    + #include <linux/irqchip/arm-gic-common.h>
    ++#include <asm/kvm_mmu.h>
    + 
    + #define PRODUCT_ID_KVM		0x4b	/* ASCII code K */
    + #define IMPLEMENTER_ARM		0x43b
    +@@ arch/arm64/kvm/vgic/vgic.h: static inline bool vgic_irq_is_multi_sgi(struct vgic_irq *irq)
    + 	return vgic_irq_get_lr_count(irq) > 1;
      }
      
     +static inline int vgic_its_read_entry_lock(struct vgic_its *its, gpa_t eaddr,
    @@ arch/arm64/kvm/vgic/vgic.h: static inline int vgic_write_guest_lock(struct kvm *
     +	if (KVM_BUG_ON(esize != sizeof(eval), kvm))
     +		return -EINVAL;
     +
    -+	return vgic_write_guest_lock(kvm, eaddr, &eval, esize);
    ++	return kvm_write_guest_lock(kvm, eaddr, &eval, esize);
     +}
     +
      /*
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.15.y       |  Success    |  Success   |