devres: fix possible use after free

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 <maxin.john@gmail.com>
Reviewed-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/irq/devres.c b/kernel/irq/devres.c
index 1ef4ffc..bd8e788 100644 (file)
--- a/kernel/irq/devres.c
+++ b/kernel/irq/devres.c
@@ -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);

diff --git a/lib/devres.c b/lib/devres.c
index 6efddf5..7c0e953 100644 (file)
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -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);
 

diff --git a/mm/dmapool.c b/mm/dmapool.c
index 03bf3bb..fbb58e3 100644 (file)
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -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);