On Thu, Aug 8, 2024 at 9:40 AM Stephen Smalley <stephen.smalley.work@xxxxxxxxx> wrote: > > On Thu, Aug 8, 2024 at 9:09 AM Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote: > > > > This reverts commit 68df1baf158fddc07b6f0333e4c81fe1ccecd6ff. > > > > The selinux only want to check whether the VMA range is within the heap > > range or not, but vma_is_initial_heap() helper will check the intersection > > between the two ranges, which leads to some issue, let's turn back to the > > original validation. > > > > Reported-by: Marc Reisner <reisner.marc@xxxxxxxxx> > > Closes: https://lore.kernel.org/all/ZrPmoLKJEf1wiFmM@xxxxxxxxxxxxxxx/ > > Fixes: 68df1baf158f ("selinux: use vma_is_initial_stack() and vma_is_initial_heap()") > > Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> > > I was only going to recommend reverting the change to the heap check > but in case Paul is fine with a straight revert, > Acked-by: Stephen Smalley <stephen.smalley.work@xxxxxxxxx> I was hoping that the mm folks would put together a quick patch to fix what looks like a problem with the helper, but I'm not sure when that is going to happen and with other callers I don't want to change the helper and break a different part of the kernel. Unfortunately that leaves us with needing a revert, but like Stephen said, I think reverting just the heap helper is the right thing to do right now; I also want to put a comment in there for the next time someone tries to re-add the vma_is_initial_heap(). Give me some time, I'll have a patch out for this later today. > > --- > > security/selinux/hooks.c | 7 +++++-- > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > > index 81fbfa5b80d4..f5805d4b0aec 100644 > > --- a/security/selinux/hooks.c > > +++ b/security/selinux/hooks.c > > @@ -3845,10 +3845,13 @@ static int selinux_file_mprotect(struct vm_area_struct *vma, > > if (default_noexec && > > (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { > > int rc = 0; > > - if (vma_is_initial_heap(vma)) { > > + if (vma->vm_start >= vma->vm_mm->start_brk && > > + vma->vm_end <= vma->vm_mm->brk) { > > rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, > > PROCESS__EXECHEAP, NULL); > > - } else if (!vma->vm_file && (vma_is_initial_stack(vma) || > > + } else if (!vma->vm_file && > > + ((vma->vm_start <= vma->vm_mm->start_stack && > > + vma->vm_end >= vma->vm_mm->start_stack) || > > vma_is_stack_for_current(vma))) { > > rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, > > PROCESS__EXECSTACK, NULL); > > -- > > 2.41.0 -- paul-moore.com
