Messages in this thread | | | Date | Tue, 27 Oct 2020 14:22:19 +0000 | From | Dave Martin <> | Subject | Re: BTI interaction between seccomp filters in systemd and glibc mprotect calls, causing service failures |
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On Mon, Oct 26, 2020 at 05:45:42PM +0100, Florian Weimer via Libc-alpha wrote: > * Dave Martin via Libc-alpha: > > > Would it now help to add something like: > > > > int mchangeprot(void *addr, size_t len, int old_flags, int new_flags) > > { > > int ret = -EINVAL; > > mmap_write_lock(current->mm); > > if (all vmas in [addr .. addr + len) have > > their mprotect flags set to old_flags) { > > > > ret = mprotect(addr, len, new_flags); > > } > > > > mmap_write_unlock(current->mm); > > return ret; > > } > > I suggested something similar as well. Ideally, the interface would > subsume pkey_mprotect, though, and have a separate flags argument from > the protection flags. But then we run into argument list length limits. > > Thanks, > Florian
I suppose. Assuming that a syscall filter can inspect memory, we might be able to bundle arguments into a struct if necessary.
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Cheers ---Dave
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