From: chenzefeng <chenzefeng2@huawei.com>
Date: Tue, 6 Aug 2019 07:46:33 +0000 (+0800)
Subject: ia64:unwind: fix double free for mod->arch.init_unw_table
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=06e87c95045cd1a26c405a387ee4ccce45c7a8db;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

ia64:unwind: fix double free for mod->arch.init_unw_table

[ Upstream commit c5e5c48c16422521d363c33cfb0dcf58f88c119b ]

The function free_module in file kernel/module.c as follow:

void free_module(struct module *mod) {
	......
	module_arch_cleanup(mod);
	......
	module_arch_freeing_init(mod);
	......
}

Both module_arch_cleanup and module_arch_freeing_init function
would free the mod->arch.init_unw_table, which cause double free.

Here, set mod->arch.init_unw_table = NULL after remove the unwind
table to avoid double free.

Signed-off-by: chenzefeng <chenzefeng2@huawei.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/arch/ia64/kernel/module.c b/arch/ia64/kernel/module.c
index 853b5611a894..95e8d130e123 100644
--- a/arch/ia64/kernel/module.c
+++ b/arch/ia64/kernel/module.c
@@ -913,8 +913,12 @@ module_finalize (const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *mo
 void
 module_arch_cleanup (struct module *mod)
 {
-	if (mod->arch.init_unw_table)
+	if (mod->arch.init_unw_table) {
 		unw_remove_unwind_table(mod->arch.init_unw_table);
-	if (mod->arch.core_unw_table)
+		mod->arch.init_unw_table = NULL;
+	}
+	if (mod->arch.core_unw_table) {
 		unw_remove_unwind_table(mod->arch.core_unw_table);
+		mod->arch.core_unw_table = NULL;
+	}
 }