From ff7e0055bb5ddbbb320cdd8dfd3e18672bddd2ad Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@amacapital.net>
Date: Sat, 16 Aug 2014 04:13:37 +0930
Subject: [PATCH] module: Clean up ro/nx after early module load failures
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: stable@vger.kernel.org # v3.16
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
kernel/module.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/module.c b/kernel/module.c
index 6f69463f00665..03214bd288e9a 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3304,6 +3304,11 @@ 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();
--
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