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From: Gen Zhang <blackgod016574@gmail.com>
To: lizhijian@cn.fujitsu.com
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] initramfs: Fix a missing-check bug in init/initramfs.c
Date: Wed, 22 May 2019 09:04:55 +0800	[thread overview]
Message-ID: <20190522010455.GA4093@zhanggen-UX430UQ> (raw)

In dir_add(), de and de->name are allocated by kmalloc() and kstrdup().
And de->name is dereferenced in the following codes. However, memory
allocation functions such as kmalloc() and kstrdup() may fail.
Dereferencing this de->name null pointer may cause the kernel go wrong.
Thus we should check this allocation.
Further, if kstrdup() returns NULL, we should free de and panic().

Signed-off-by: Gen Zhang <blackgod016574@gmail.com>

---
diff --git a/init/initramfs.c b/init/initramfs.c
index 178130f..dc8063f 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -125,6 +125,10 @@ static void __init dir_add(const char *name, time64_t mtime)
 		panic("can't allocate dir_entry buffer");
 	INIT_LIST_HEAD(&de->list);
 	de->name = kstrdup(name, GFP_KERNEL);
+	if (!de->name) {
+		kfree(de);
+		panic("can't allocate dir_entry name buffer");
+	}
 	de->mtime = mtime;
 	list_add(&de->list, &dir_list);
 }

             reply	other threads:[~2019-05-22  1:05 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-22  1:04 Gen Zhang [this message]
     [not found] ` <2c246472-bb1c-1063-1370-33da04af27d0@cn.fujitsu.com>
2019-05-22  2:07   ` Gen Zhang
2019-05-22  6:29   ` [PATCH v2] " Gen Zhang
     [not found]     ` <fd0277b7-a9a1-d2f6-c8bc-d8b8619c647e@intel.com>
2019-05-22  7:26       ` Gen Zhang

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