On Tue, Aug 11, 2020 at 06:01:35PM +0200, Jessica Yu wrote: > +++ Mauro Carvalho Chehab [11/08/20 17:27 +0200]: > > Em Tue, 11 Aug 2020 16:55:24 +0200 > > pet...@infradead.org escreveu: > > > > > On Tue, Aug 11, 2020 at 04:34:27PM +0200, Mauro Carvalho Chehab wrote: > > > > [33] .plt PROGBITS 0000000000000340 00035c80 > > > > 0000000000000001 0000000000000000 WAX 0 0 1 > > > > [34] .init.plt NOBITS 0000000000000341 00035c81 > > > > 0000000000000001 0000000000000000 WA 0 0 1 > > > > [35] .text.ftrace[...] PROGBITS 0000000000000342 00035c81 > > > > 0000000000000001 0000000000000000 WAX 0 0 1 > > > > > > .plt and .text.ftrace_tramplines are buggered. > > > > > > arch/arm64/kernel/module.lds even marks then as NOLOAD. > > > > Hmm... Shouldn't the code at module_enforce_rwx_sections() or at > > load_module() ignore such sections instead of just rejecting probing > > all modules? > > > > I mean, if the existing toolchain is not capable of excluding > > those sections, either the STRICT_MODULE_RWX hardening should be > > disabled, if a broken toolchain is detected or some runtime code > > should handle such sections on a different way. > > Hi Mauro, thanks for providing the readelf output. The sections marked 'WAX' > are indeed the reason why the module loader is rejecting them. > > Interesting, my cross-compiled modules do not have the executable flag - > > [38] .plt NOBITS 0000000000000340 00038fc0 > 0000000000000001 0000000000000000 WA 0 0 1 > [39] .init.plt NOBITS 0000000000000341 00038fc0 > 0000000000000001 0000000000000000 WA 0 0 1 > [40] .text.ftrace_tram NOBITS 0000000000000342 00038fc0 > 0000000000000001 0000000000000000 WA 0 0 1
FWIW, I also see the same output as you for both of the GCC 9 and Clang 11 builds I have kicking around, and there are no WAX sections in sight. Will
