Messages in this thread | | | From | Paul Moore <> | Date | Thu, 28 Jun 2018 20:23:02 -0400 | Subject | Re: [PATCH] selinux: move user accesses in selinuxfs out of locked regions |
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On Tue, Jun 26, 2018 at 8:15 AM Stephen Smalley <sds@tycho.nsa.gov> wrote: > On 06/25/2018 12:34 PM, Jann Horn wrote: > > If a user is accessing a file in selinuxfs with a pointer to a userspace > > buffer that is backed by e.g. a userfaultfd, the userspace access can > > stall indefinitely, which can block fsi->mutex if it is held. > > > > For sel_read_policy(), remove the locking, since this method doesn't seem > > to access anything that requires locking. > > > > For sel_read_bool(), move the user access below the locked region. > > > > For sel_write_bool() and sel_commit_bools_write(), move the user access > > up above the locked region. > > > > Cc: stable@vger.kernel.org > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > > Signed-off-by: Jann Horn <jannh@google.com> > > Only question I have is wrt the Fixes line, i.e. was this an issue until userfaultfd was introduced, and if not, > do we need it to be back-ported any further than the commit which introduced it.
Considering we are talking about v2.6.12 I have to wonder if anyone is bothering with backports for kernels that old. Even the RHEL-5.x based systems are at least on v2.6.18.
Regardless, I think this is fine to merge as-is; thanks everyone.
> Otherwise, you can add my > Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
-- paul moore www.paul-moore.com
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