From a5c19628acd4b7d236fcd941d400b465dc027284 Mon Sep 17 00:00:00 2001 From: deraadt Date: Mon, 7 Nov 2022 20:41:38 +0000 Subject: [PATCH] Since the introduction of automatic immutable from the kernel, the munmap() of ld.so boot.text region is now (silently) failing because the region is contained within the text LOAD, which is immutable. So create a new btext LOAD with flags PF_X|PF_R|PF_OPENBSD_MUTABLE, and place all boot.text objects in there. This LOAD must also be page-aligned so it doesn't skip unmapping some of the object region, previously it was hilariously unaligned. Similar changes for other architectures coming after more testing. ok kettenis and guenther seemed to like it also --- libexec/ld.so/aarch64/ld.script | 6 ++++-- libexec/ld.so/amd64/ld.script | 8 +++++--- 2 files changed, 9 insertions(+), 5 deletions(-) diff --git a/libexec/ld.so/aarch64/ld.script b/libexec/ld.so/aarch64/ld.script index d0231259a0b..3c4434bb8b4 100644 --- a/libexec/ld.so/aarch64/ld.script +++ b/libexec/ld.so/aarch64/ld.script @@ -2,6 +2,7 @@ PHDRS { rodata PT_LOAD FILEHDR PHDRS FLAGS (4); text PT_LOAD; + btext PT_LOAD FLAGS (0x08000005); data PT_LOAD; random PT_OPENBSD_RANDOMIZE; relro PT_GNU_RELRO; @@ -22,13 +23,14 @@ SECTIONS /* TEXT */ . = ALIGN(0x10000); .text : { *(.text .text.*) } :text - . = ALIGN(0x1000); .boot.text : { + . = ALIGN(0x1000); boot_text_start = .; *(.boot.text) + . = ALIGN(0x1000); boot_text_end = .; - } :text + } :btext /* RELRO DATA */ . = DATA_SEGMENT_ALIGN (0x10000, 0x1000); diff --git a/libexec/ld.so/amd64/ld.script b/libexec/ld.so/amd64/ld.script index 5629239dd52..29f4e14d844 100644 --- a/libexec/ld.so/amd64/ld.script +++ b/libexec/ld.so/amd64/ld.script @@ -2,6 +2,7 @@ PHDRS { rodata PT_LOAD FILEHDR PHDRS FLAGS (4); text PT_LOAD; + btext PT_LOAD FLAGS (0x08000005); data PT_LOAD; random PT_OPENBSD_RANDOMIZE; relro PT_GNU_RELRO; @@ -20,14 +21,15 @@ SECTIONS .eh_frame : { *(.eh_frame) } :rodata /* TEXT */ - . = ALIGN(0x100000) + (. & (0x100000 - 1)) + 0; + . = ALIGN(0x1000); .boot.text : { + . = ALIGN(0x1000); boot_text_start = .; *(.boot.text) + . = ALIGN(0x1000); boot_text_end = .; - } :text =0xcccccccc - . = ALIGN(0x1000); + } :btext =0xcccccccc .text : { *(.text .text.*) } :text =0xcccccccc /* RELRO DATA */ -- 2.20.1