I understand that I ought to have included this in the previous checkin. MFC after: 3 days
and that my description of the appropriateness of len==0 passed to mmap was imprecise. I regret the error. Doug Moore On 6/9/19 10:07 PM, Doug Moore wrote: > Author: dougm > Date: Mon Jun 10 03:07:10 2019 > New Revision: 348843 > URL: https://svnweb.freebsd.org/changeset/base/348843 > > Log: > There are times when a len==0 parameter to mmap is okay. But on a > 32-bit machine, a len parameter just a few bytes short of 4G, rounded > up to a page boundary and hitting zero then, is not okay. Return > failure in that case. > > Reported by: pho > Reviewed by: alc, kib (mentor) > Tested by: pho > Differential Revision: https://reviews.freebsd.org/D20580 > > Modified: > head/sys/vm/vm_mmap.c > > Modified: head/sys/vm/vm_mmap.c > ============================================================================== > --- head/sys/vm/vm_mmap.c Sun Jun 9 22:55:21 2019 (r348842) > +++ head/sys/vm/vm_mmap.c Mon Jun 10 03:07:10 2019 (r348843) > @@ -257,7 +257,10 @@ kern_mmap(struct thread *td, uintptr_t addr0, size_t s > > /* Adjust size for rounding (on both ends). */ > size += pageoff; /* low end... */ > - size = (vm_size_t) round_page(size); /* hi end */ > + /* Check for rounding up to zero. */ > + if (round_page(size) < size) > + return (EINVAL); > + size = round_page(size); /* hi end */ > > /* Ensure alignment is at least a page and fits in a pointer. */ > align = flags & MAP_ALIGNMENT_MASK; > _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
