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improve error checking for modifcations to mmap len parameter
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Authored by dougm on Jun 10 2019, 7:31 PM.

Details

Summary

Change the check for 'size' wrapping around to zero in kern_mmap to account for both the lower and upper bound modifications. Change the error returned to ENOMEM. Rename the parameter size to len and make size a local variable that stores the value of len after it has been modified.

This addresses concerns expressed by Bruce Evans after r348843.

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Repository
rS FreeBSD src repository
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Event Timeline

dougm created this revision.Jun 10 2019, 7:31 PM
kib accepted this revision.Jun 10 2019, 7:57 PM
This revision is now accepted and ready to land.Jun 10 2019, 7:57 PM
markj accepted this revision.Jun 10 2019, 9:17 PM
This revision was automatically updated to reflect the committed changes.
pho added a comment.Jun 10 2019, 9:51 PM

I do not seem to be able to boot successfully with this patch?

alc added a subscriber: alc.Jun 10 2019, 9:59 PM
alc added inline comments.
head/sys/vm/vm_mmap.c
262

Shouldn't this be (size < len)?

dougm added inline comments.Jun 10 2019, 10:01 PM
head/sys/vm/vm_mmap.c
262

Yes, it should.