The driver currently sets the handler data and the chained handler in
two separate steps. This creates a theoretical race window where an
interrupt could fire after the handler is set but before the data is
assigned, leading to a NULL pointer dereference.

Replace the two calls with irq_set_chained_handler_and_data() to set
both the handler and its data atomically under the irq_desc->lock.

Signed-off-by: Chen Ni <[email protected]>
---
 arch/powerpc/platforms/52xx/mpc52xx_gpt.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c 
b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
index 7748b6641a3c..e8163fdee69a 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
@@ -253,8 +253,7 @@ mpc52xx_gpt_irq_setup(struct mpc52xx_gpt_priv *gpt, struct 
device_node *node)
                return;
        }
 
-       irq_set_handler_data(cascade_virq, gpt);
-       irq_set_chained_handler(cascade_virq, mpc52xx_gpt_irq_cascade);
+       irq_set_chained_handler_and_data(cascade_virq, mpc52xx_gpt_irq_cascade, 
gpt);
 
        /* If the GPT is currently disabled, then change it to be in Input
         * Capture mode.  If the mode is non-zero, then the pin could be
-- 
2.25.1


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