[v5] irqchip/gic-v3-its: Fix double free on error

[PATCH v5 2/2] irqchip/gic-v3-its: remove BUG_ON in its_vpe_irq_domain_alloc

Posted by Guanrui Huang 1 year, 9 months ago

This BUG_ON() is useless, because the same effect will be obtained 
by letting the code run its course and vm being dereferenced,
triggering an exception.

So just remove this check.

Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Guanrui Huang <guanrui.huang@linux.alibaba.com>
---
 drivers/irqchip/irq-gic-v3-its.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 2305f6b524a9..55c83e19719d 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -4521,8 +4521,6 @@ static int its_vpe_irq_domain_alloc(struct irq_domain *domain, unsigned int virq
 	struct page *vprop_page;
 	int base, nr_ids, i, err = 0;
 
-	BUG_ON(!vm);
-
 	bitmap = its_lpi_alloc(roundup_pow_of_two(nr_irqs), &base, &nr_ids);
 	if (!bitmap)
 		return -ENOMEM;
-- 
2.36.1

Re: [PATCH v5 2/2] irqchip/gic-v3-its: remove BUG_ON in its_vpe_irq_domain_alloc

Posted by Zenghui Yu 1 year, 9 months ago

On 2024/4/18 14:10, Guanrui Huang wrote:
> This BUG_ON() is useless, because the same effect will be obtained
> by letting the code run its course and vm being dereferenced,
> triggering an exception.
> 
> So just remove this check.
> 
> Acked-by: Marc Zyngier <maz@kernel.org>
> Signed-off-by: Guanrui Huang <guanrui.huang@linux.alibaba.com>

Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>

[tip: irq/core] irqchip/gic-v3-its: Remove BUG_ON in its_vpe_irq_domain_alloc

Posted by tip-bot2 for Guanrui Huang 1 year, 9 months ago

The following commit has been merged into the irq/core branch of tip:

Commit-ID:     382d2ffe86efb1e2fa803d2cf17e5bfc34e574f3
Gitweb:        https://git.kernel.org/tip/382d2ffe86efb1e2fa803d2cf17e5bfc34e574f3
Author:        Guanrui Huang <guanrui.huang@linux.alibaba.com>
AuthorDate:    Thu, 18 Apr 2024 14:10:53 +08:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 25 Apr 2024 14:38:24 +02:00

irqchip/gic-v3-its: Remove BUG_ON in its_vpe_irq_domain_alloc

This BUG_ON() is useless, because the same effect will be obtained 
by letting the code run its course and vm being dereferenced,
triggering an exception.

So just remove this check.

Signed-off-by: Guanrui Huang <guanrui.huang@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240418061053.96803-3-guanrui.huang@linux.alibaba.com

---
 drivers/irqchip/irq-gic-v3-its.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 20f9542..98e5593 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -4526,8 +4526,6 @@ static int its_vpe_irq_domain_alloc(struct irq_domain *domain, unsigned int virq
 	struct page *vprop_page;
 	int base, nr_ids, i, err = 0;
 
-	BUG_ON(!vm);
-
 	bitmap = its_lpi_alloc(roundup_pow_of_two(nr_irqs), &base, &nr_ids);
 	if (!bitmap)
 		return -ENOMEM;