Commit ff7e0055 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Rusty Russell

module: Clean up ro/nx after early module load failures

The commit

    4982223e 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: default avatarAndy Lutomirski <luto@amacapital.net>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent c9d26423
...@@ -3304,6 +3304,11 @@ static int load_module(struct load_info *info, const char __user *uargs, ...@@ -3304,6 +3304,11 @@ static int load_module(struct load_info *info, const char __user *uargs,
mutex_lock(&module_mutex); mutex_lock(&module_mutex);
module_bug_cleanup(mod); module_bug_cleanup(mod);
mutex_unlock(&module_mutex); 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: ddebug_cleanup:
dynamic_debug_remove(info->debug); dynamic_debug_remove(info->debug);
synchronize_sched(); synchronize_sched();
......
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