On Fri 06-01-17 16:12:55, Gu Zheng wrote:
> This change was missed the tmpfs modification in In CVE-2016-7097
> commit 073931017b49d9458aa351605b43a7e34598caef
> posix_acl: Clear SGID bit when setting file permissions.
> It can test by xfstest generic/375, which failed to clear
> setgid bit in the following test case on tmpfs:
>
> touch $testfile
> chown 100:100 $testfile
> chmod 2755 $testfile
> _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile
>
> Signed-off-by: Gu Zheng <guzhe...@huawei.com>
Ah, good catch. One comment below:
> diff --git a/fs/posix_acl.c b/fs/posix_acl.c
> index 5955220..d014dff 100644
> --- a/fs/posix_acl.c
> +++ b/fs/posix_acl.c
> @@ -922,11 +922,10 @@ int simple_set_acl(struct inode *inode, struct
> posix_acl *acl, int type)
> int error;
>
> if (type == ACL_TYPE_ACCESS) {
> - error = posix_acl_equiv_mode(acl, &inode->i_mode);
> - if (error < 0)
> - return 0;
> - if (error == 0)
> - acl = NULL;
> + error = posix_acl_update_mode(inode,
> + &inode->i_mode, &acl);
> + if (error > 0)
> + return error;
Uh, why this error > 0 check? AFAIU it should be:
if (error < 0)
return 0;
As it used to be before...
Honza
--
Jan Kara <j...@suse.com>
SUSE Labs, CR
