From: JingYi Hou houjingyi647@gmail.com
[ Upstream commit d0bae4a0e3d8c5690a885204d7eb2341a5b4884d ]
In sock_getsockopt(), 'optlen' is fetched the first time from userspace. 'len < 0' is then checked. Then in condition 'SO_MEMINFO', 'optlen' is fetched the second time from userspace.
If change it between two fetches may cause security problems or unexpected behaivor, and there is no reason to fetch it a second time.
To fix this, we need to remove the second fetch.
Signed-off-by: JingYi Hou houjingyi647@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/sock.c | 3 --- 1 file changed, 3 deletions(-)
--- a/net/core/sock.c +++ b/net/core/sock.c @@ -1358,9 +1358,6 @@ int sock_getsockopt(struct socket *sock, { u32 meminfo[SK_MEMINFO_VARS];
- if (get_user(len, optlen)) - return -EFAULT; - sk_get_meminfo(sk, meminfo);
len = min_t(unsigned int, len, sizeof(meminfo));