linux-kernel - [PATCH] tools/lib/slab: Fix potential NULL pointer dereference in kmalloc()

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Date: Sat, 25 May 2024 03:14:59 +0800
From: Kuan-Wei Chiu <visitorckw@...il.com>
To: akpm@...ux-foundation.org
Cc: jserv@...s.ncku.edu.tw,
	linux-kernel@...r.kernel.org,
	Kuan-Wei Chiu <visitorckw@...il.com>
Subject: [PATCH] tools/lib/slab: Fix potential NULL pointer dereference in kmalloc()

In kmalloc(), add a check to ensure that the pointer 'ret' is not NULL
before attempting to memset it when the __GFP_ZERO flag is set. This
prevents a potential NULL pointer dereference.

Signed-off-by: Kuan-Wei Chiu <visitorckw@...il.com>
---
 tools/lib/slab.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/lib/slab.c b/tools/lib/slab.c
index 959997fb0652..aeaf535b422a 100644
--- a/tools/lib/slab.c
+++ b/tools/lib/slab.c
@@ -22,7 +22,7 @@ void *kmalloc(size_t size, gfp_t gfp)
 	uatomic_inc(&kmalloc_nr_allocated);
 	if (kmalloc_verbose)
 		printf("Allocating %p from malloc\n", ret);
-	if (gfp & __GFP_ZERO)
+	if (gfp & __GFP_ZERO && ret)
 		memset(ret, 0, size);
 	return ret;
 }
-- 
2.34.1