On Thu, Jun 4, 2020 at 4:08 PM Stephen Smalley <stephen.smalley.work@xxxxxxxxx> wrote: > > As reported in https://github.com/SELinuxProject/selinux/issues/248, > setfiles -r (rootpath) fails when the alternate root contains a symlink > that is correct relative to the alternate root but not in the current root. > This is a regression introduced by commit e016502c0a26 ("libselinux: Save > digest of all partial matches for directory"). Do not call statfs(2) here > if acting on a symbolic link. Unfortunately there is no lstatfs() call. > Ensure that we initialize the statfs buffer always. If the supplied > file is a symlink, then we don't need to worry about the later tests of > filesystem type because we wouldn't be setting the digest anyway and > we are not performing a full sysfs relabel. While here, fix the earlier > test for a directory to use the correct test. > > Reproducer: > $ mkdir /root/my-chroot && echo foo > /root/my-chroot/link-target && ln -s /link-target /root/my-chroot/symlink > $ echo "/root/my-chroot/symlink" | setfiles -vFi -r /root/my-chroot -f - /etc/selinux/targeted/contexts/files/file_contexts > > Before: > setfiles: statfs(/root/my-chroot/symlink) failed: No such file or directory > > After: > Relabeled /root/my-chroot/symlink from unconfined_u:object_r:admin_home_t:s0 to system_u:object_r:default_t:s0 > > Fixes: https://github.com/SELinuxProject/selinux/issues/248 > Fixes: e016502c0a26 ("libselinux: Save digest of all partial matches for directory") > Signed-off-by: Stephen Smalley <stephen.smalley.work@xxxxxxxxx> Anyone want to ack or object to this patch? > --- > libselinux/src/selinux_restorecon.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/libselinux/src/selinux_restorecon.c b/libselinux/src/selinux_restorecon.c > index 91dfeb66..d1ce830c 100644 > --- a/libselinux/src/selinux_restorecon.c > +++ b/libselinux/src/selinux_restorecon.c > @@ -938,7 +938,7 @@ int selinux_restorecon(const char *pathname_orig, > } > > /* Skip digest if not a directory */ > - if ((sb.st_mode & S_IFDIR) != S_IFDIR) > + if (!S_ISDIR(sb.st_mode)) > setrestorecondigest = false; > > if (!flags.recurse) { > @@ -952,7 +952,8 @@ int selinux_restorecon(const char *pathname_orig, > } > > /* Obtain fs type */ > - if (statfs(pathname, &sfsb) < 0) { > + memset(&sfsb, 0, sizeof sfsb); > + if (!S_ISLNK(sb.st_mode) && statfs(pathname, &sfsb) < 0) { > selinux_log(SELINUX_ERROR, > "statfs(%s) failed: %s\n", > pathname, strerror(errno)); > -- > 2.23.3 >
