The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x b97e8a2f7130 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024061913-unpainted-labrador-5bb5@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b97e8a2f7130a4b30d1502003095833d16c028b3 Mon Sep 17 00:00:00 2001 From: Hagar Hemdan hagarhem@amazon.com Date: Fri, 31 May 2024 16:21:44 +0000 Subject: [PATCH] irqchip/gic-v3-its: Fix potential race condition in its_vlpi_prop_update()
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, hoist the locking there instead of sprinkling the locking all over the place.
This bug was discovered using Coverity Static Analysis Security Testing (SAST) by Synopsys, Inc.
[ tglx: Use guard() instead of goto ]
Fixes: 015ec0386ab6 ("irqchip/gic-v3-its: Add VLPI configuration handling") Suggested-by: Marc Zyngier maz@kernel.org Signed-off-by: Hagar Hemdan hagarhem@amazon.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: stable@vger.kernel.org Reviewed-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20240531162144.28650-1-hagarhem@amazon.com
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 40ebf1726393..3c755d5dad6e 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) @@ -1992,6 +1970,8 @@ static int its_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu_info) if (!is_v4(its_dev->its)) return -EINVAL;
+ guard(raw_spinlock_irq)(&its_dev->event_map.vlpi_lock); + /* Unmap request? */ if (!info) return its_vlpi_unmap(d);