| Message ID | 20161230234232.4221-1-ebiggers3@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
From: Eric Biggers <ebiggers3@gmail.com> Date: Fri, 30 Dec 2016 17:42:32 -0600 > From: Eric Biggers <ebiggers@google.com> > > ->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. > > Fixes: 86741ec25462 ("net: core: Add a UID field to struct sock.") > Signed-off-by: Eric Biggers <ebiggers@google.com> Lorenzo, please review. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, Dec 31, 2016 at 8:42 AM, Eric Biggers <ebiggers3@gmail.com> wrote: > ->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. > [...] > - if (!err) { > + if (!err && (iattr->ia_valid & ATTR_UID)) { Oops. Thanks for fixing this. Unit tested in https://android-review.googlesource.com/316594 . Tested-by: Lorenzo Colitti <lorenzo@google.com> Acked-by: Lorenzo Colitti <lorenzo@google.com> -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Lorenzo Colitti <lorenzo@google.com> Date: Sun, 1 Jan 2017 16:57:23 +0900 > On Sat, Dec 31, 2016 at 8:42 AM, Eric Biggers <ebiggers3@gmail.com> wrote: >> ->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. >> [...] >> - if (!err) { >> + if (!err && (iattr->ia_valid & ATTR_UID)) { > > Oops. Thanks for fixing this. Unit tested in > https://android-review.googlesource.com/316594 . > > Tested-by: Lorenzo Colitti <lorenzo@google.com> > Acked-by: Lorenzo Colitti <lorenzo@google.com> Applied, thanks everyone. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/socket.c b/net/socket.c index 8487bf136e5c..a8c2307590b8 100644 --- a/net/socket.c +++ b/net/socket.c @@ -537,7 +537,7 @@ 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(d_inode(dentry)); sock->sk->sk_uid = iattr->ia_uid;