[PATCH 1/2] tun: Use memdup_user() rather than duplicating its implementation

SF Markus Elfring
2016-08-20T07:35:24Z

Date: Sat, 20 Aug 2016 08:54:15 +0200

Reuse existing functionality from memdup_user() instead of keeping
duplicate source code.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/net/tun.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 9c8b5bc..a1aeccb 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -731,14 +731,9 @@ static int update_filter(struct tap_filter *filter, void __user *arg)
}

alen = ETH_ALEN * uf.count;
- addr = kmalloc(alen, GFP_KERNEL);
- if (!addr)
- return -ENOMEM;
-
- if (copy_from_user(addr, arg + sizeof(uf), alen)) {
- err = -EFAULT;
- goto done;
- }
+ addr = memdup_user(arg + sizeof(uf), alen);
+ if (IS_ERR(addr))
+ return PTR_ERR(addr);

/* The filter is updated without holding any locks. Which is
* perfectly safe. We disable it first and in the worst
--
2.9.3