Commit d0bae4a0 authored Jun 17, 2019 by JingYi Hou Committed by David S. Miller Jun 18, 2019

net: remove duplicate fetch in sock_getsockopt



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>

parent d0f84d08

net/core/sock.c

+0 −3

Original line number	Diff line number	Diff line
		@@ -1477,9 +1477,6 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
		{
		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));

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