[rds-devel] [Patch net] rds: avoid calling sock_kfree_s() on allocation failure
David Miller
davem at davemloft.net
Tue Oct 14 14:03:11 PDT 2014
From: Cong Wang <xiyou.wangcong at gmail.com>
Date: Tue, 14 Oct 2014 12:35:08 -0700
> From: Cong Wang <cwang at twopensource.com>
>
> It is okay to free a NULL pointer but not okay to mischarge the socket optmem
> accounting. Compile test only.
>
> Reported-by: rucsoftsec at gmail.com
> Cc: Chien Yen <chien.yen at oracle.com>
> Cc: Stephen Hemminger <stephen at networkplumber.org>
> Signed-off-by: Cong Wang <cwang at twopensource.com>
> Signed-off-by: Cong Wang <xiyou.wangcong at gmail.com>
Applied, and I'm going to add the following bug check to the tree too.
====================
[PATCH] net: Trap attempts to call sock_kfree_s() with a NULL pointer.
Unlike normal kfree() it is never right to call sock_kfree_s() with
a NULL pointer, because sock_kfree_s() also has the side effect of
discharging the memory from the sockets quota.
Signed-off-by: David S. Miller <davem at davemloft.net>
---
net/core/sock.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/core/sock.c b/net/core/sock.c
index b4f3ea2..15e0c67 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1718,6 +1718,8 @@ EXPORT_SYMBOL(sock_kmalloc);
*/
void sock_kfree_s(struct sock *sk, void *mem, int size)
{
+ if (WARN_ON_ONCE(!mem))
+ return;
kfree(mem);
atomic_sub(size, &sk->sk_omem_alloc);
}
--
1.7.11.7
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