Re: [PATCH] MIPS: Prevent READ_IMPLIES_EXEC propagation

[Maciej W. Rozycki]

On Tue, 7 Jul 2020, Tiezhu Yang wrote:

> In the MIPS architecture, we should clear the security-relevant
> flag READ_IMPLIES_EXEC in the function SET_PERSONALITY2() of the
> file arch/mips/include/asm/elf.h.
> 
> Otherwise, with this flag set, PROT_READ implies PROT_EXEC for
> mmap to make memory executable that is not safe, because this
> condition allows an attacker to simply jump to and execute bytes
> that are considered to be just data [1].

 Why isn't the arrangement made with `mips_elf_read_implies_exec' 
sufficient?

  Maciej