From 64e16fbbf49ce81b37841480d14b0caf5753c98e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Tue, 16 Mar 2021 17:44:56 +0400 Subject: [PATCH] util: fix use-after-free in module_load_one MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit g_hash_table_add always retains ownership of the pointer passed in as the key. Its return status merely indicates whether the added entry was new, or replaced an existing entry. Thus key must never be freed after this method returns. Spotted by ASAN: ==2407186==ERROR: AddressSanitizer: heap-use-after-free on address 0x6020003ac4f0 at pc 0x7ffff766659c bp 0x7fffffffd1d0 sp 0x7fffffffc980 READ of size 1 at 0x6020003ac4f0 thread T0 #0 0x7ffff766659b (/lib64/libasan.so.6+0x8a59b) #1 0x7ffff6bfa843 in g_str_equal ../glib/ghash.c:2303 #2 0x7ffff6bf8167 in g_hash_table_lookup_node ../glib/ghash.c:493 #3 0x7ffff6bf9b78 in g_hash_table_insert_internal ../glib/ghash.c:1598 #4 0x7ffff6bf9c32 in g_hash_table_add ../glib/ghash.c:1689 #5 0x5555596caad4 in module_load_one ../util/module.c:233 #6 0x5555596ca949 in module_load_one ../util/module.c:225 #7 0x5555596ca949 in module_load_one ../util/module.c:225 #8 0x5555596cbdf4 in module_load_qom_all ../util/module.c:349 Typical C bug... Fixes: 90629122d2e ("module: use g_hash_table_add()") Cc: qemu-stable@nongnu.org Signed-off-by: Marc-André Lureau Reviewed-by: Daniel P. Berrangé Message-Id: <20210316134456.3243102-1-marcandre.lureau@redhat.com> Reviewed-by: Philippe Mathieu-Daudé --- util/module.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/util/module.c b/util/module.c index cbe89fede6..7661d0f623 100644 --- a/util/module.c +++ b/util/module.c @@ -230,10 +230,11 @@ bool module_load_one(const char *prefix, const char *lib_name, bool mayfail) } } - if (!g_hash_table_add(loaded_modules, module_name)) { + if (g_hash_table_contains(loaded_modules, module_name)) { g_free(module_name); return true; } + g_hash_table_add(loaded_modules, module_name); search_dir = getenv("QEMU_MODULE_DIR"); if (search_dir != NULL) {