[PATCH v3] powerpc/mpic: Fix memory leak of mpic on error paths

[Jyoti Gupta <jyoti@linux.ibm.com>]

mpic_alloc() allocates struct mpic (and optionally the protected
sources bitmap) but does not free them when mpic_setup_error_int() or
irq_domain_create_linear() fails, leaking the memory.

Free the bitmap and the mpic in the common error path before
dropping the device node reference.

Fixes: 996983b75ceb ("powerpc/mpic: Search for open-pic device-tree node if NULL")
Signed-off-by: Jyoti Gupta <jyoti@linux.ibm.com>
---

Changelog
===========
v2->v3:
 + Introduce 'err_free_mpic' unwind label to cleanly free mpic and mpic->protected
 + Link to v2: https://lore.kernel.org/all/20260930180919.335930-1-jyoti@linux.ibm.com/ 
 
---
---
arch/powerpc/sysdev/mpic.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 257886ec3f70..d799cf4da7bd 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -1389,7 +1389,7 @@ struct mpic * __init mpic_alloc(struct device_node *node,
 		if (fsl_version >= 0x401) {
 			ret = mpic_setup_error_int(mpic, intvec_top - 13);
 			if (ret)
-				return NULL;
+				goto err_free_mpic;
 		}
 
 	}
@@ -1488,12 +1488,8 @@ struct mpic * __init mpic_alloc(struct device_node *node,
 						 intvec_top,
 						 &mpic_host_ops, mpic);
 
-	/*
-	 * FIXME: The code leaks the MPIC object and mappings here; this
-	 * is very unlikely to fail but it ought to be fixed anyways.
-	 */
 	if (mpic->irqhost == NULL)
-		return NULL;
+		goto err_free_mpic;
 
 	/* Display version */
 	switch (greg_feature & MPIC_GREG_FEATURE_VERSION_MASK) {
@@ -1526,6 +1522,9 @@ struct mpic * __init mpic_alloc(struct device_node *node,
 
 	return mpic;
 
+err_free_mpic:
+	bitmap_free(mpic->protected);
+	kfree(mpic);
 err_of_node_put:
 	of_node_put(node);
 	return NULL;
-- 
2.55.0