From: Satoru Takeuchi <satoru.takeuchi@gmail.com>
Date: Wed, 20 Mar 2013 00:58:51 +0000 (+1030)
Subject: hw_random: free rng_buffer at module exit
X-Git-Tag: firefly_0821_release~3680^2~805^2~2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b7d44d9487a11e835de10908f4ab30b4290c0b7f;p=firefly-linux-kernel-4.4.55.git

hw_random: free rng_buffer at module exit

rng-core module allocates rng_buffer by kmalloc() since commit
f7f154f1246ccc5a0a7e9ce50932627d60a0c878. But this buffer won't be
freed and there is a memory leak possibility at module exit.

Signed-off-by: Satoru Takeuchi <satoru.takeuchi@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 69ae5972713c..a0f7724852eb 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -380,6 +380,15 @@ void hwrng_unregister(struct hwrng *rng)
 }
 EXPORT_SYMBOL_GPL(hwrng_unregister);
 
+static void __exit hwrng_exit(void)
+{
+	mutex_lock(&rng_mutex);
+	BUG_ON(current_rng);
+	kfree(rng_buffer);
+	mutex_unlock(&rng_mutex);
+}
+
+module_exit(hwrng_exit);
 
 MODULE_DESCRIPTION("H/W Random Number Generator (RNG) driver");
 MODULE_LICENSE("GPL");