linux-kernel - [PATCH] Fix memory overwriting issue when copy an address to user space

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAEQHRfB2f4x2r9Sk1+ixAFjUTcFQArv9wtWfjq3igGfUgZBhXw@mail.gmail.com>
Date:   Fri, 17 Jul 2020 10:31:54 +0000
From:   lebon zhou <lebon.zhou@...il.com>
To:     davem@...emloft.net, kuba@...nel.org
Cc:     linux-kernel@...r.kernel.org
Subject: [PATCH] Fix memory overwriting issue when copy an address to user space

When application provided buffer size less than sockaddr_storage, then
kernel will overwrite some memory area which may cause memory corruption,
e.g.: in recvmsg case, let msg_name=malloc(8) and msg_namelen=8, then
usually application can call recvmsg successful but actually application
memory get corrupted.

Fix to return EINVAL when application buffer size less than
sockaddr_storage.

Signed-off-by: lebon.zhou <lebon.zhou@...il.com>
---
 net/socket.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/socket.c b/net/socket.c
index 976426d03f09..dc32b1b899df 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -229,7 +229,7 @@ static int move_addr_to_user(struct
sockaddr_storage *kaddr, int klen,
         return err;
     if (len > klen)
         len = klen;
-    if (len < 0)
+    if (len < 0 || len < klen)
         return -EINVAL;
     if (len) {
         if (audit_sockaddr(klen, kaddr))
-- 
2.22.0