Quoting Seth Forshee (seth.forshee@xxxxxxxxxxxxx): > Superblock level remounts are currently restricted to global > CAP_SYS_ADMIN, as is the path for changing the root mount to > read only on umount. Loosen both of these permission checks to > also allow CAP_SYS_ADMIN in any namespace which is privileged > towards the userns which originally mounted the filesystem. > > Signed-off-by: Seth Forshee <seth.forshee@xxxxxxxxxxxxx> > Acked-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> > --- Acked-by: Serge Hallyn <serge.hallyn@xxxxxxxxxxxxx> > fs/namespace.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/namespace.c b/fs/namespace.c > index 18fc58760aec..b00a765895e7 100644 > --- a/fs/namespace.c > +++ b/fs/namespace.c > @@ -1510,7 +1510,7 @@ static int do_umount(struct mount *mnt, int flags) > * Special case for "unmounting" root ... > * we just try to remount it readonly. > */ > - if (!capable(CAP_SYS_ADMIN)) > + if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) > return -EPERM; > down_write(&sb->s_umount); > if (!(sb->s_flags & MS_RDONLY)) > @@ -2199,7 +2199,7 @@ static int do_remount(struct path *path, int flags, int mnt_flags, > down_write(&sb->s_umount); > if (flags & MS_BIND) > err = change_mount_flags(path->mnt, flags); > - else if (!capable(CAP_SYS_ADMIN)) > + else if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) > err = -EPERM; > else > err = do_remount_sb(sb, flags, data, 0); > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
