Messages in this thread | | | Date | Wed, 3 Jun 2009 10:35:10 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: Security fix for remapping of page 0 (was [PATCH] Change ZERO_SIZE_PTR to point at unmapped space) |
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On Wed, 3 Jun 2009, Alan Cox wrote: > > One way you could approach this would be to write a security module for > non SELINUX users - one that did one thing alone - decide whether the app > being run was permitted to map the low 64K perhaps by checking the > security label on the file.
Unnecessary. I really think that 99% of all people are perfectly fine with just the "mmap_min_addr" rule, and no more.
The rest could just use SElinux or set it to zero. It's not like allowing mmap's at NULL is a huge problem. Sure, it allows a certain kind of attack vector, but it's by no means an easy or common one - you need to already have gotten fairly good local access to take advantage of it.
Linus
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