diff options
| author | Jan Kara <jack@suse.cz> | 2016-12-14 13:24:50 +0100 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2016-12-23 08:56:35 -0500 |
| commit | 62fa696b7b435e93ed114dd6a23aa0881d7f81b9 (patch) | |
| tree | b79fe7082c8370a323a83b947804d7340c823f35 /fs/btrfs | |
| parent | de42b9559d0c540152260d484dbc70b3e81f8738 (diff) | |
posix_acl: Clear SGID bit when setting file permissions
[ Upstream commit 073931017b49d9458aa351605b43a7e34598caef ]
When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2). Fix that.
References: CVE-2016-7097
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Philipp Hahn <hahn@univention.de>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/acl.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c index 9a0124a95851..fb3e64d37cb4 100644 --- a/fs/btrfs/acl.c +++ b/fs/btrfs/acl.c @@ -83,11 +83,9 @@ static int __btrfs_set_acl(struct btrfs_trans_handle *trans, case ACL_TYPE_ACCESS: name = POSIX_ACL_XATTR_ACCESS; if (acl) { - ret = posix_acl_equiv_mode(acl, &inode->i_mode); - if (ret < 0) + ret = posix_acl_update_mode(inode, &inode->i_mode, &acl); + if (ret) return ret; - if (ret == 0) - acl = NULL; } ret = 0; break; |