On Thu, Dec 23, 2021 at 11:20:07AM +0100, Greg KH wrote: > On Thu, Dec 23, 2021 at 10:57:33AM +0100, Christian Brauner wrote: > > From: Christian Brauner <christian.brauner@xxxxxxxxxx> > > > > Ceph always inherits the SGID bit if it is set on the parent inode, > > while the generic inode_init_owner does not do this in a few cases where > > it can create a possible security problem (cf. [1]). > > > > Update ceph to strip the SGID bit just as inode_init_owner would. > > > > This bug was detected by the mapped mount testsuite in [3]. The > > testsuite tests all core VFS functionality and semantics with and > > without mapped mounts. That is to say it functions as a generic VFS > > testsuite in addition to a mapped mount testsuite. While working on > > mapped mount support for ceph, SIGD inheritance was the only failing > > test for ceph after the port. > > > > The same bug was detected by the mapped mount testsuite in XFS in > > January 2021 (cf. [2]). > > > > [1]: commit 0fa3ecd87848 ("Fix up non-directory creation in SGID directories") > > [2]: commit 01ea173e103e ("xfs: fix up non-directory creation in SGID directories") > > [3]: https://git.kernel.org/fs/xfs/xfstests-dev.git > > > > Cc: stable@xxxxxxxxxxxxxxx (adapted to v5.10) > > Signed-off-by: Christian Brauner <christian.brauner@xxxxxxxxxx> > > Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx> > > Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx> > > --- > > fs/ceph/file.c | 18 +++++++++++++++--- > > 1 file changed, 15 insertions(+), 3 deletions(-) > > What is the git commit id in Linus's tree? commit fd84bfdddd169c219c3a637889a8b87f70a072c2 Author: Christian Brauner <christian.brauner@xxxxxxxxxx> Date: Mon Nov 29 12:16:39 2021 +0100 ceph: fix up non-directory creation in SGID directories