From f77fd98aaa992b7156f37af8e57beafe6b6cc5f0 Mon Sep 17 00:00:00 2001
From: Zijun Hu <quic_zijuhu@quicinc.com>
Date: Tue, 2 Jul 2024 22:51:50 +0800
Subject: [PATCH] devres: Fix devm_krealloc() wasting memory
commit c884e3249f753dcef7a2b2023541ac1dc46b318e upstream.
Driver API devm_krealloc() calls alloc_dr() with wrong argument
@total_new_size, so causes more memory to be allocated than required
fix this memory waste by using @new_size as the argument for alloc_dr().
Fixes: f82485722e5d ("devres: provide devm_krealloc()")
Cc: stable@vger.kernel.org
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/1719931914-19035-2-git-send-email-quic_zijuhu@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/base/devres.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index 586e9a75c..452541ce0 100755
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -901,9 +901,12 @@ void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
/*
* Otherwise: allocate new, larger chunk. We need to allocate before
* taking the lock as most probably the caller uses GFP_KERNEL.
+ * alloc_dr() will call check_dr_size() to reserve extra memory
+ * for struct devres automatically, so size @new_size user request
+ * is delivered to it directly as devm_kmalloc() does.
*/
new_dr = alloc_dr(devm_kmalloc_release,
- total_new_size, gfp, dev_to_node(dev));
+ new_size, gfp, dev_to_node(dev));
if (!new_dr)
return NULL;