From: Andy Lutomirski <[email protected]>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit ff7e0055bb5ddbbb320cdd8dfd3e18672bddd2ad upstream.

The commit

    4982223e51e8 module: set nx before marking module MODULE_STATE_COMING.

introduced a regression: if a module fails to parse its arguments or
if mod_sysfs_setup fails, then the module's memory will be freed
while still read-only.  Anything that reuses that memory will crash
as soon as it tries to write to it.

Cc: [email protected] # v3.16
Cc: Rusty Russell <[email protected]>
Signed-off-by: Andy Lutomirski <[email protected]>
Signed-off-by: Rusty Russell <[email protected]>
Signed-off-by: Jiri Slaby <[email protected]>
---
 kernel/module.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kernel/module.c b/kernel/module.c
index 3edb91fabc7a..a97785308f25 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3332,6 +3332,11 @@ static int load_module(struct load_info *info, const 
char __user *uargs,
        mutex_lock(&module_mutex);
        module_bug_cleanup(mod);
        mutex_unlock(&module_mutex);
+
+       /* we can't deallocate the module until we clear memory protection */
+       unset_module_init_ro_nx(mod);
+       unset_module_core_ro_nx(mod);
+
  ddebug_cleanup:
        dynamic_debug_remove(info->debug);
        synchronize_sched();
-- 
2.3.4

--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to