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authorPeter Zijlstra <peterz@infradead.org>2020-08-18 15:57:39 +0200
committerIngo Molnar <mingo@kernel.org>2020-09-01 09:58:04 +0200
commit0db6e3734b130207026df1e78455fa98ca1d6f50 (patch)
treec00e5bd613f2825d75dee5199b40aae30c4b0e73 /kernel/jump_label.c
parent59cc8e0a906ea23190922e5e0252e5b5a60d70c2 (diff)
downloadlinux-0db6e3734b130207026df1e78455fa98ca1d6f50.tar.gz
jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved()
Nothing ensures the module exists while we're iterating
mod->jump_entries in __jump_label_mod_text_reserved(), take a module
reference to ensure the module sticks around.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20200818135804.504501338@infradead.org
Diffstat (limited to 'kernel/jump_label.c')
-rw-r--r--kernel/jump_label.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index cdb3ffab128b..e661c61b3d6b 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -539,19 +539,25 @@ static void static_key_set_mod(struct static_key *key,
 static int __jump_label_mod_text_reserved(void *start, void *end)
 {
 	struct module *mod;
+	int ret;
 
 	preempt_disable();
 	mod = __module_text_address((unsigned long)start);
 	WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);
+	if (!try_module_get(mod))
+		mod = NULL;
 	preempt_enable();
 
 	if (!mod)
 		return 0;
 
-
-	return __jump_label_text_reserved(mod->jump_entries,
+	ret = __jump_label_text_reserved(mod->jump_entries,
 				mod->jump_entries + mod->num_jump_entries,
 				start, end);
+
+	module_put(mod);
+
+	return ret;
 }
 
 static void __jump_label_mod_update(struct static_key *key)