its_vlpi_prop_update() calls lpi_write_config() which obtains the
mapping information for a VLPI without lock held. So it could race
with its_vlpi_unmap().
Since all calls from its_irq_set_vcpu_affinity() require the same
lock to be held. So instead of peppering the locking all over the
place, we hoist the locking into its_irq_set_vcpu_affinity().
This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.
Fixes: 015ec0386ab6 ("irqchip/gic-v3-its: Add VLPI configuration handling")
Suggested-by: Marc Zyngier <[email protected]>
Signed-off-by: Hagar Hemdan <[email protected]>
---
v2: moved the lock to its_irq_set_vcpu_affinity().
Only compile-tested, no access to HW.
---
drivers/irqchip/irq-gic-v3-its.c | 65 +++++++++++++-------------------
1 file changed, 27 insertions(+), 38 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 40ebf1726393..f9e824ad1523 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1846,28 +1846,22 @@ static int its_vlpi_map(struct irq_data *d, struct its_cmd_info *info)
{
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
u32 event = its_get_event_id(d);
- int ret = 0;
if (!info->map)
return -EINVAL;
- raw_spin_lock(&its_dev->event_map.vlpi_lock);
-
if (!its_dev->event_map.vm) {
struct its_vlpi_map *maps;
maps = kcalloc(its_dev->event_map.nr_lpis, sizeof(*maps),
GFP_ATOMIC);
- if (!maps) {
- ret = -ENOMEM;
- goto out;
- }
+ if (!maps)
+ return -ENOMEM;
its_dev->event_map.vm = info->map->vm;
its_dev->event_map.vlpi_maps = maps;
} else if (its_dev->event_map.vm != info->map->vm) {
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}
/* Get our private copy of the mapping information */
@@ -1899,46 +1893,32 @@ static int its_vlpi_map(struct irq_data *d, struct its_cmd_info *info)
its_dev->event_map.nr_vlpis++;
}
-out:
- raw_spin_unlock(&its_dev->event_map.vlpi_lock);
- return ret;
+ return 0;
}
static int its_vlpi_get(struct irq_data *d, struct its_cmd_info *info)
{
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
struct its_vlpi_map *map;
- int ret = 0;
-
- raw_spin_lock(&its_dev->event_map.vlpi_lock);
map = get_vlpi_map(d);
- if (!its_dev->event_map.vm || !map) {
- ret = -EINVAL;
- goto out;
- }
+ if (!its_dev->event_map.vm || !map)
+ return -EINVAL;
/* Copy our mapping information to the incoming request */
*info->map = *map;
-out:
- raw_spin_unlock(&its_dev->event_map.vlpi_lock);
- return ret;
+ return 0;
}
static int its_vlpi_unmap(struct irq_data *d)
{
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
u32 event = its_get_event_id(d);
- int ret = 0;
- raw_spin_lock(&its_dev->event_map.vlpi_lock);
-
- if (!its_dev->event_map.vm || !irqd_is_forwarded_to_vcpu(d)) {
- ret = -EINVAL;
- goto out;
- }
+ if (!its_dev->event_map.vm || !irqd_is_forwarded_to_vcpu(d))
+ return -EINVAL;
/* Drop the virtual mapping */
its_send_discard(its_dev, event);
@@ -1962,9 +1942,7 @@ static int its_vlpi_unmap(struct irq_data *d)
kfree(its_dev->event_map.vlpi_maps);
}
-out:
- raw_spin_unlock(&its_dev->event_map.vlpi_lock);
- return ret;
+ return 0;
}
static int its_vlpi_prop_update(struct irq_data *d, struct its_cmd_info *info)
@@ -1987,29 +1965,40 @@ static int its_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
{
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
struct its_cmd_info *info = vcpu_info;
+ int ret;
/* Need a v4 ITS */
if (!is_v4(its_dev->its))
return -EINVAL;
+ raw_spin_lock(&its_dev->event_map.vlpi_lock);
+
/* Unmap request? */
- if (!info)
- return its_vlpi_unmap(d);
+ if (!info) {
+ ret = its_vlpi_unmap(d);
+ goto out;
+ }
switch (info->cmd_type) {
case MAP_VLPI:
- return its_vlpi_map(d, info);
+ ret = its_vlpi_map(d, info);
+ break;
case GET_VLPI:
- return its_vlpi_get(d, info);
+ ret = its_vlpi_get(d, info);
+ break;
case PROP_UPDATE_VLPI:
case PROP_UPDATE_AND_INV_VLPI:
- return its_vlpi_prop_update(d, info);
+ ret = its_vlpi_prop_update(d, info);
+ break;
default:
- return -EINVAL;
+ ret = -EINVAL;
}
+out:
+ raw_spin_unlock(&its_dev->event_map.vlpi_lock);
+ return ret;
}
static struct irq_chip its_irq_chip = {
--
2.40.1