From 198c7fd61a14b8f69a3ed9fe4324850e88eb4910 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 30 Dec 2016 17:42:32 -0600 Subject: [PATCH] net: socket: don't set sk_uid to garbage value in ->setattr() ->setattr() was recently implemented for socket files to sync the socket inode's uid to the new 'sk_uid' member of struct sock. It does this by copying over the ia_uid member of struct iattr. However, ia_uid is actually only valid when ATTR_UID is set in ia_valid, indicating that the uid is being changed, e.g. by chown. Other metadata operations such as chmod or utimes leave ia_uid uninitialized. Therefore, sk_uid could be set to a "garbage" value from the stack. Fix this by only copying the uid over when ATTR_UID is set. [backport of net e1a3a60a2ebe991605acb14cd58e39c0545e174e] Bug: 16355602 Change-Id: I20e53848e54282b72a388ce12bfa88da5e3e9efe Fixes: 86741ec25462 ("net: core: Add a UID field to struct sock.") Signed-off-by: Eric Biggers Tested-by: Lorenzo Colitti Acked-by: Lorenzo Colitti Signed-off-by: David S. Miller Git-commit: 10487d4e83e94f6f5ac0912f8af04ad7dd29f071 Git-repo: https://android.googlesource.com/kernel/common.git Signed-off-by: Srinivasarao P --- net/socket.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/socket.c b/net/socket.c index 8b3585fd4103..399bb4767ca6 100644 --- a/net/socket.c +++ b/net/socket.c @@ -531,7 +531,7 @@ int sockfs_setattr(struct dentry *dentry, struct iattr *iattr) { int err = simple_setattr(dentry, iattr); - if (!err) { + if (!err && (iattr->ia_valid & ATTR_UID)) { struct socket *sock = SOCKET_I(dentry->d_inode); sock->sk->sk_uid = iattr->ia_uid;