[PATCH] dma-buf: Fix memory leak in dma_buf_set_name

From: Bharath Vedartham
Date: Fri Aug 16 2019 - 14:00:44 EST

This patch fixes a memory leak bug reported by syzbot. Link to the
bug is given at [1].

A local variable name is used to hold the copied user buffer string
using strndup_user. strndup_user allocates memory using
kmalloc_track_caller in memdup_user. This kmalloc allocation needs to be
followed by a kfree.

This patch has been tested by a compile test.

[1] https://syzkaller.appspot.com/bug?id=ce692a3aa13e00e335e090be7846c6eb60ddff7a

Reported-by: syzbot+b2098bc44728a4efb3e9@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Bharath Vedartham <linux.bhar@xxxxxxxxx>
drivers/dma-buf/dma-buf.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index f45bfb2..9798f6d 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -342,6 +342,7 @@ static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf)
dmabuf->name = name;
+ kfree(name);