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authorChristoffer Dall <christoffer.dall@linaro.org>2016-08-01 20:25:33 +0200
committerChristoffer Dall <christoffer.dall@linaro.org>2016-08-10 11:41:35 +0200
commit99e5e886a0a59df267ff6838f763b789847df982 (patch)
treea3f144ed79a1cd132ab8c3667a25cedc685e0461 /virt
parentfd837b08d98c0c9f4f31998f2ed55b9d8694082c (diff)
downloadlinux-stericsson-99e5e886a0a59df267ff6838f763b789847df982.tar.gz
KVM: arm64: vgic-its: Handle errors from vgic_add_lpi
During low memory conditions, we could be dereferencing a NULL pointer when vgic_add_lpi fails to allocate memory. Consider for example this call sequence: vgic_its_cmd_handle_mapi itte->irq = vgic_add_lpi(kvm, lpi_nr); update_lpi_config(kvm, itte->irq, NULL); ret = kvm_read_guest(kvm, propbase + irq->intid ^^^^ kaboom? Instead, return an error pointer from vgic_add_lpi and check the return value from its single caller. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/arm/vgic/vgic-its.c21
1 files changed, 17 insertions, 4 deletions
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 1bd8adbeae26..d06330abd5e8 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -51,7 +51,7 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid)
irq = kzalloc(sizeof(struct vgic_irq), GFP_KERNEL);
if (!irq)
- return NULL;
+ return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&irq->lpi_list);
INIT_LIST_HEAD(&irq->ap_list);
@@ -522,7 +522,8 @@ static void its_free_itte(struct kvm *kvm, struct its_itte *itte)
list_del(&itte->itte_list);
/* This put matches the get in vgic_add_lpi. */
- vgic_put_irq(kvm, itte->irq);
+ if (itte->irq)
+ vgic_put_irq(kvm, itte->irq);
kfree(itte);
}
@@ -713,10 +714,11 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
u32 device_id = its_cmd_get_deviceid(its_cmd);
u32 event_id = its_cmd_get_id(its_cmd);
u32 coll_id = its_cmd_get_collection(its_cmd);
- struct its_itte *itte;
+ struct its_itte *itte, *new_itte = NULL;
struct its_device *device;
struct its_collection *collection, *new_coll = NULL;
int lpi_nr;
+ struct vgic_irq *irq;
device = find_its_device(its, device_id);
if (!device)
@@ -747,13 +749,24 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
return -ENOMEM;
}
+ new_itte = itte;
itte->event_id = event_id;
list_add_tail(&itte->itte_list, &device->itt_head);
}
itte->collection = collection;
itte->lpi = lpi_nr;
- itte->irq = vgic_add_lpi(kvm, lpi_nr);
+
+ irq = vgic_add_lpi(kvm, lpi_nr);
+ if (IS_ERR(irq)) {
+ if (new_coll)
+ vgic_its_free_collection(its, coll_id);
+ if (new_itte)
+ its_free_itte(kvm, new_itte);
+ return PTR_ERR(irq);
+ }
+ itte->irq = irq;
+
update_affinity_itte(kvm, itte);
/*