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devres: Fix possible use after free

PATCH RESEND Maxin B John 1 participant 1 message Jun 15, 2011

Subsystems (4)
Memory management Library code MM misc IRQ
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Share & tools
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Maxin B John

author Reviewed-by Rolf Eike Beer Acked-by Tejun Heo
#0 lore raw

devres uses the pointer value as key after it's freed, which is safe but triggers spurious use-after-free warnings on some static analysis tools. Rearrange code to avoid such warnings.

Signed-off-by Maxin B. John <[email protected]>
Reviewed-by Rolf Eike Beer <[email protected]>
Acked-by Tejun Heo <[email protected]>

---

kernel/irq/devres.c +1 -1
index 1ef4ffc..bd8e788 100644
@@ -87,8 +87,8 @@ void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id)
 {
 	struct irq_devres match_data = { irq, dev_id };
 
-	free_irq(irq, dev_id);
 	WARN_ON(devres_destroy(dev, devm_irq_release, devm_irq_match,
 			       &match_data));
+	free_irq(irq, dev_id);
 }
 EXPORT_SYMBOL(devm_free_irq);
lib/devres.c +1 -1
index 6efddf5..7c0e953 100644
@@ -79,9 +79,9 @@ EXPORT_SYMBOL(devm_ioremap_nocache);
  */
 void devm_iounmap(struct device *dev, void __iomem *addr)
 {
-	iounmap(addr);
 	WARN_ON(devres_destroy(dev, devm_ioremap_release, devm_ioremap_match,
 			       (void *)addr));
+	iounmap(addr);
 }
 EXPORT_SYMBOL(devm_iounmap);
mm/dmapool.c +1 -1
index 03bf3bb..fbb58e3 100644
@@ -500,7 +500,7 @@ void dmam_pool_destroy(struct dma_pool *pool)
 {
 	struct device *dev = pool->dev;
 
-	dma_pool_destroy(pool);
 	WARN_ON(devres_destroy(dev, dmam_pool_release, dmam_pool_match, pool));
+	dma_pool_destroy(pool);
 }
 EXPORT_SYMBOL(dmam_pool_destroy);