@@ -3305,7 +3305,7 @@ core_param(module_blacklist, module_blacklist, charp, 0400);
* layout_sections() can put it in the right place.
* Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
*/
-static char *ro_after_init_sections[] = {
+static const char * const ro_after_init_sections[] = {
".data..ro_after_init",
/*
@@ -3314,6 +3314,12 @@ static char *ro_after_init_sections[] = {
* annotated as such at module load time.
*/
"__jump_table",
+
+ /*
+ * Used for SRCU structures which need to be initialized/cleaned up
+ * by the SRCU notifiers
+ */
+ "___srcu_struct_ptrs",
};
static struct module *layout_and_allocate(struct load_info *info, int flags)
@@ -3336,7 +3342,7 @@ static struct module *layout_and_allocate(struct load_info *info, int flags)
info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
/* Set sh_flags for read-only after init sections */
- for (i = 0; ro_after_init_sections[i]; i++) {
+ for (i = 0; i < ARRAY_SIZE(ro_after_init_sections); i++) {
ndx = find_sec(info, ro_after_init_sections[i]);
if (ndx)
info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
Since commit title ("srcu: Allocate per-CPU data for DEFINE_SRCU() in modules"), modules that call DEFINE_{STATIC,}SRCU will have a new array of srcu_struct pointers which is used by srcu code to initialize and clean up these structures. There is no reason for this array of pointers to be writable, and can cause security or other hidden bugs. Mark these are read-only after the module init has completed. Suggested-by: paulmck@linux.vnet.ibm.com Suggested-by: keescook@chromium.org Acked-by: keescook@chromium.org Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> --- kernel/module.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)