On 03/08/2017 07:40 PM, Kees Cook wrote:
On Mon, Mar 6, 2017 at 10:11 AM, Kees Cook <keesc...@chromium.org> wrote:On Fri, Mar 3, 2017 at 7:23 PM, Daniel Borkmann <dan...@iogearbox.net> wrote:Latter shows that memory protecting the kernel seems not working either on i386 (!). Test suite output:[...] [ 12.692836] Write protecting the kernel text: 13416k [ 12.693309] Write protecting the kernel read-only data: 5292k [ 12.693802] rodata_test: test data was not read only [...] Work-around to not enable ARCH_HAS_SET_MEMORY for i386 is not optimal as it doesn't fix the issue in presumably broken set_memory_*(), but it at least avoids people avoid having to deal with random corruptions that are hard to track down for the time being until a real fix can be found.Wow. Uhm, so, something must be _really_ broken. i386 should have no problem with using the set_memory_*() functions. The fact that DEBUG_RODATA_TEST failed is also pretty crazy, but may be unrelated (that test was just refactored too).I'm not able to reproduce this. I built Linus's tree and rodata_test passes for me on i386. I tried the .config from Fengguang (with RODATA_TEST=y added), but it still passes for me: https://lkml.org/lkml/2017/3/1/344 I wonder if something change changed already in the tree? Can you still reproduce this?
I'll answer in a bit an will move the discussion over to the other
thread on the same topic ("[net/bpf] 3051bf36c2 BUG: unable to handle
kernel paging request at 0000a7cf" [1]) with you, Laura and Dave in
Cc as well.
[1] https://lkml.org/lkml/2017/3/8/620
