On Fri, Apr 15, 2022 at 01:18:57AM +0000, xuyang2018.jy@xxxxxxxxxxx wrote:
> on 2022/4/14 23:57, Darrick J. Wong wrote:
> > On Thu, Apr 14, 2022 at 03:57:17PM +0800, Yang Xu wrote:
> >> inode_sgid_strip() function is used to strip S_ISGID mode
> >> when creat/open/mknod file.
> >>
> >> Reviewed-by: Christian Brauner (Microsoft)<brauner@xxxxxxxxxx>
> >> Signed-off-by: Yang Xu<xuyang2018.jy@xxxxxxxxxxx>
> >> ---
> >> fs/inode.c | 18 ++++++++++++++++++
> >> include/linux/fs.h | 3 ++-
> >> 2 files changed, 20 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/fs/inode.c b/fs/inode.c
> >> index 9d9b422504d1..d63264998855 100644
> >> --- a/fs/inode.c
> >> +++ b/fs/inode.c
> >> @@ -2405,3 +2405,21 @@ struct timespec64 current_time(struct inode *inode)
> >> return timestamp_truncate(now, inode);
> >> }
> >> EXPORT_SYMBOL(current_time);
> >> +
> >> +void inode_sgid_strip(struct user_namespace *mnt_userns, struct inode *dir,
> >> + umode_t *mode)
> >> +{
> >> + if (!dir || !(dir->i_mode& S_ISGID))
> >> + return;
> >> + if ((*mode& (S_ISGID | S_IXGRP)) != (S_ISGID | S_IXGRP))
> >> + return;
> >> + if (S_ISDIR(*mode))
> >> + return;
> >> + if (in_group_p(i_gid_into_mnt(mnt_userns, dir)))
> >> + return;
> >> + if (capable_wrt_inode_uidgid(mnt_userns, dir, CAP_FSETID))
> >> + return;
> >> +
> >> + *mode&= ~S_ISGID;
> >> +}
> >
> > Thanks for cleaning up the multiple if statements from last time.
> >
> > I still would like to see patch 1 replace the code in inode_init_owner
> > so that we can compare before and after in the same patch. Patch 2 can
> > then be solely about moving the callsite around the VFS.
> >
> Ok, then patch 1 can named as"fs/inode: move inode sgid strip operation
> from inode_init_owner into inode_sgid_strip". What do you think about it?
Sounds good to me.
--D
>
> Best Regards
> Yang Xu
> > --D
> >
> >> +EXPORT_SYMBOL(inode_sgid_strip);
> >> diff --git a/include/linux/fs.h b/include/linux/fs.h
> >> index bbde95387a23..94d94219fe7c 100644
> >> --- a/include/linux/fs.h
> >> +++ b/include/linux/fs.h
> >> @@ -1897,7 +1897,8 @@ extern long compat_ptr_ioctl(struct file *file, unsigned int cmd,
> >> void inode_init_owner(struct user_namespace *mnt_userns, struct inode *inode,
> >> const struct inode *dir, umode_t mode);
> >> extern bool may_open_dev(const struct path *path);
> >> -
> >> +void inode_sgid_strip(struct user_namespace *mnt_userns, struct inode *dir,
> >> + umode_t *mode);
> >> /*
> >> * This is the "filldir" function type, used by readdir() to let
> >> * the kernel specify what kind of dirent layout it wants to have.
> >> --
> >> 2.27.0
> >>
