Commit 7fe28d7e authored by Jing Zhang's avatar Jing Zhang Committed by Oliver Upton
Browse files

KVM: arm64: vgic-its: Add a data length check in vgic_its_save_* 



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
when the fault occurs, KVM_BUG_ON() is used. And the other BUG_ON()s
are replaced together.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarKunkun Jiang <jiangkunkun@huawei.com>
[Jing: Update with the new entry read/write helpers]
Signed-off-by: default avatarJing Zhang <jingzhangos@google.com>
Link: https://lore.kernel.org/r/20241107214137.428439-4-jingzhangos@google.com


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 81983758

arch/arm64/kvm/vgic/vgic-its.c

+8 −12
Original line number Diff line number Diff line
@@ -2086,7 +2086,6 @@ static int scan_its_table(struct vgic_its *its, gpa_t base, int size, u32 esz, 
static int vgic_its_save_ite(struct vgic_its *its, struct its_device *dev,

			      struct its_ite *ite, gpa_t gpa, int ite_esz)

{

	struct kvm *kvm = its->dev->kvm;

	u32 next_offset;

	u64 val;
@@ -2095,7 +2094,8 @@ static int vgic_its_save_ite(struct vgic_its *its, struct its_device *dev, 
	       ((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 vgic_its_write_entry_lock(its, gpa, val, ite_esz);

}



/**
@@ -2239,7 +2239,6 @@ static int vgic_its_restore_itt(struct vgic_its *its, struct its_device *dev) 
static int vgic_its_save_dte(struct vgic_its *its, struct its_device *dev,

			     gpa_t ptr, int dte_esz)

{

	struct kvm *kvm = its->dev->kvm;

	u64 val, itt_addr_field;

	u32 next_offset;
@@ -2250,7 +2249,8 @@ static int vgic_its_save_dte(struct vgic_its *its, struct its_device *dev, 
	       (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 vgic_its_write_entry_lock(its, ptr, val, dte_esz);

}



/**
@@ -2437,7 +2437,8 @@ static int vgic_its_save_cte(struct vgic_its *its, 
	       ((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 vgic_its_write_entry_lock(its, gpa, val, esz);

}



/*
@@ -2453,8 +2454,7 @@ static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz) 
	u64 val;

	int ret;



	BUG_ON(esz > sizeof(val));

	ret = kvm_read_guest_lock(kvm, gpa, &val, esz);

	ret = vgic_its_read_entry_lock(its, gpa, &val, esz);

	if (ret)

		return ret;

	val = le64_to_cpu(val);
@@ -2492,7 +2492,6 @@ static int vgic_its_save_collection_table(struct vgic_its *its) 
	u64 baser = its->baser_coll_table;

	gpa_t gpa = GITS_BASER_ADDR_48_to_52(baser);

	struct its_collection *collection;

	u64 val;

	size_t max_size, filled = 0;

	int ret, cte_esz = abi->cte_esz;
@@ -2516,10 +2515,7 @@ static int vgic_its_save_collection_table(struct vgic_its *its) 
	 * table is not fully filled, add a last dummy element

	 * with valid bit unset

	 */

	val = 0;

	BUG_ON(cte_esz > sizeof(val));

	ret = vgic_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

+23 −0
Original line number Diff line number Diff line
@@ -146,6 +146,29 @@ static inline int vgic_write_guest_lock(struct kvm *kvm, gpa_t gpa, 
	return ret;

}



static inline int vgic_its_read_entry_lock(struct vgic_its *its, gpa_t eaddr,

					   u64 *eval, unsigned long esize)

{

	struct kvm *kvm = its->dev->kvm;



	if (KVM_BUG_ON(esize != sizeof(*eval), kvm))

		return -EINVAL;



	return kvm_read_guest_lock(kvm, eaddr, eval, esize);



}



static inline int vgic_its_write_entry_lock(struct vgic_its *its, gpa_t eaddr,

					    u64 eval, unsigned long esize)

{

	struct kvm *kvm = its->dev->kvm;



	if (KVM_BUG_ON(esize != sizeof(eval), kvm))

		return -EINVAL;



	return vgic_write_guest_lock(kvm, eaddr, &eval, esize);

}



/*

 * This struct provides an intermediate representation of the fields contained

 * in the GICH_VMCR and ICH_VMCR registers, such that code exporting the GIC