Messages in this thread | | | Date | Tue, 9 May 2017 01:56:59 -0700 | From | Christoph Hellwig <> | Subject | Re: [kernel-hardening] Re: [PATCH v9 1/4] syscalls: Verify address limit before returning to user-mode |
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On Tue, May 09, 2017 at 08:45:22AM +0200, Ingo Molnar wrote: > We only have ~115 code blocks in the kernel that set/restore KERNEL_DS, it would > be a pity to add a runtime check to every system call ...
I think we should simply strive to remove all of them that aren't in core scheduler / arch code. Basically evetyytime we do the
oldfs = get_fs(); set_fs(KERNEL_DS); .. set_fs(oldfs);
trick we're doing something wrong, and there should always be better ways to archive it. E.g. using iov_iter with a ITER_KVEC type consistently would already remove most of them.
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