.opd section contains function descriptors used to locate
functions in the kernel. If someone is able to modify a
function descriptor he will be able to run arbitrary
kernel function instead of another.
To avoid that, move .opd section inside read-only memory.
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
arch/powerpc/kernel/vmlinux.lds.S | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S
b/arch/powerpc/kernel/vmlinux.lds.S
index 40bdefe9caa7..18e42c74abdd 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -143,6 +143,12 @@ SECTIONS
SOFT_MASK_TABLE(8)
RESTART_TABLE(8)
+ .opd : AT(ADDR(.opd) - LOAD_OFFSET) {
+ __start_opd = .;
+ KEEP(*(.opd))
+ __end_opd = .;
+ }
+
. = ALIGN(8);
__stf_entry_barrier_fixup : AT(ADDR(__stf_entry_barrier_fixup) -
LOAD_OFFSET) {
__start___stf_entry_barrier_fixup = .;
@@ -339,12 +345,6 @@ SECTIONS
*(.branch_lt)
}
- .opd : AT(ADDR(.opd) - LOAD_OFFSET) {
- __start_opd = .;
- KEEP(*(.opd))
- __end_opd = .;
- }
-
. = ALIGN(256);
.got : AT(ADDR(.got) - LOAD_OFFSET) {
__toc_start = .;
--
2.31.1
