]> git.karo-electronics.de Git - linux-beck.git/commit
posix_acl: Clear SGID bit when setting file permissions
authorJan Kara <jack@suse.cz>
Mon, 19 Sep 2016 15:39:09 +0000 (17:39 +0200)
committerJan Kara <jack@suse.cz>
Thu, 22 Sep 2016 08:55:32 +0000 (10:55 +0200)
commit073931017b49d9458aa351605b43a7e34598caef
tree8c4374e82e5cad92bdb589e5be417f1a94870399
parent5d3ddd84eaefffd23c028bce5610dac8726f71c1
posix_acl: Clear SGID bit when setting file permissions

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>
16 files changed:
fs/9p/acl.c
fs/btrfs/acl.c
fs/ceph/acl.c
fs/ext2/acl.c
fs/ext4/acl.c
fs/f2fs/acl.c
fs/gfs2/acl.c
fs/hfsplus/posix_acl.c
fs/jffs2/acl.c
fs/jfs/acl.c
fs/ocfs2/acl.c
fs/orangefs/acl.c
fs/posix_acl.c
fs/reiserfs/xattr_acl.c
fs/xfs/xfs_acl.c
include/linux/posix_acl.h