On Thu, Jan 14, 2021 at 8:30 AM William Roberts
<bill.c.roberts@xxxxxxxxx> wrote:
>
> On Thu, Jan 14, 2021 at 7:42 AM Petr Lautrbach <plautrba@xxxxxxxxxx> wrote:
> >
> > According to mmap(2) after the mmap() call has returned, the file
> > descriptor, fd, can be closed immediately without invalidating the
> > mapping.
> >
> > Signed-off-by: Petr Lautrbach <plautrba@xxxxxxxxxx>
> > ---
> > libselinux/src/sestatus.c | 6 ++----
> > 1 file changed, 2 insertions(+), 4 deletions(-)
> >
> > diff --git a/libselinux/src/sestatus.c b/libselinux/src/sestatus.c
> > index 9ff2785d876a..6a243b7bcdfb 100644
> > --- a/libselinux/src/sestatus.c
> > +++ b/libselinux/src/sestatus.c
> > @@ -298,11 +298,10 @@ int selinux_status_open(int fallback)
> > goto error;
> >
> > selinux_status = mmap(NULL, pagesize, PROT_READ, MAP_SHARED, fd, 0);
> > + close(fd);
> > if (selinux_status == MAP_FAILED) {
> > - close(fd);
> > goto error;
> > }
> > - selinux_status_fd = fd;
> > last_seqno = (uint32_t)(-1);
> >
> > /* sequence must not be changed during references */
> > @@ -379,6 +378,7 @@ void selinux_status_close(void)
> > avc_netlink_release_fd();
> > avc_netlink_close();
> > selinux_status = NULL;
> > + close(selinux_status_fd);
> > return;
> > }
> >
> > @@ -388,7 +388,5 @@ void selinux_status_close(void)
> > munmap(selinux_status, pagesize);
> > selinux_status = NULL;
> >
> > - close(selinux_status_fd);
> > - selinux_status_fd = -1;
> > last_seqno = (uint32_t)(-1);
> > }
> > --
> > 2.30.0
> >
>
> Nack, the fd in the mmap of the status page and the selinux_status_fd
> (avc mount) are different fd's.
> The selinux_status_fd is for the AVC netlink socket fallback. If you
> drop those hunks I'd take the patch.
Sorry I misread that, I missed the assignment from fd to that variable...
Ack, this should fix that umount issue hopefully I didn't test that though.
