From c2385eaa6c5a87cdc4e04ed589ae103ca3297c84 Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Thu, 26 Oct 2017 17:23:06 +0200 Subject: KVM: arm/arm64: vgic-its: Check GITS_BASER Valid bit before saving tables At the moment we don't properly check the GITS_BASER.Valid bit before saving the collection and device tables. On vgic_its_save_collection_table() we use the GITS_BASER gpa field whereas the Valid bit should be used. On vgic_its_save_device_tables() there is no check. This can cause various bugs, among which a subsequent fault when accessing the table in guest memory. Let's systematically check the Valid bit before doing anything. We also uniformize the code between save and restore. Signed-off-by: Eric Auger Reviewed-by: Andre Przywara Reviewed-by: Christoffer Dall Reviewed-by: Marc Zyngier Signed-off-by: Christoffer Dall --- virt/kvm/arm/vgic/vgic-its.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) (limited to 'virt/kvm') diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index e69ef7d27fde..547f12dc4d54 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -2067,11 +2067,12 @@ static int vgic_its_device_cmp(void *priv, struct list_head *a, static int vgic_its_save_device_tables(struct vgic_its *its) { const struct vgic_its_abi *abi = vgic_its_get_abi(its); + u64 baser = its->baser_device_table; struct its_device *dev; int dte_esz = abi->dte_esz; - u64 baser; - baser = its->baser_device_table; + if (!(baser & GITS_BASER_VALID)) + return 0; list_sort(NULL, &its->device_list, vgic_its_device_cmp); @@ -2215,17 +2216,17 @@ static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz) static int vgic_its_save_collection_table(struct vgic_its *its) { const struct vgic_its_abi *abi = vgic_its_get_abi(its); + u64 baser = its->baser_coll_table; + gpa_t gpa = BASER_ADDRESS(baser); struct its_collection *collection; u64 val; - gpa_t gpa; size_t max_size, filled = 0; int ret, cte_esz = abi->cte_esz; - gpa = BASER_ADDRESS(its->baser_coll_table); - if (!gpa) + if (!(baser & GITS_BASER_VALID)) return 0; - max_size = GITS_BASER_NR_PAGES(its->baser_coll_table) * SZ_64K; + max_size = GITS_BASER_NR_PAGES(baser) * SZ_64K; list_for_each_entry(collection, &its->collection_list, coll_list) { ret = vgic_its_save_cte(its, collection, gpa, cte_esz); @@ -2256,17 +2257,18 @@ static int vgic_its_save_collection_table(struct vgic_its *its) static int vgic_its_restore_collection_table(struct vgic_its *its) { const struct vgic_its_abi *abi = vgic_its_get_abi(its); + u64 baser = its->baser_coll_table; int cte_esz = abi->cte_esz; size_t max_size, read = 0; gpa_t gpa; int ret; - if (!(its->baser_coll_table & GITS_BASER_VALID)) + if (!(baser & GITS_BASER_VALID)) return 0; - gpa = BASER_ADDRESS(its->baser_coll_table); + gpa = BASER_ADDRESS(baser); - max_size = GITS_BASER_NR_PAGES(its->baser_coll_table) * SZ_64K; + max_size = GITS_BASER_NR_PAGES(baser) * SZ_64K; while (read < max_size) { ret = vgic_its_restore_cte(its, gpa, cte_esz); -- cgit v1.2.3-55-g7522