efi: fix NULL-deref in init error path

[ Upstream commit 703c13fe3c9af557d312f5895ed6a5fda2711104 ]

In cases where runtime services are not supported or have been disabled,
the runtime services workqueue will never have been allocated.

Do not try to destroy the workqueue unconditionally in the unlikely
event that EFI initialisation fails to avoid dereferencing a NULL
pointer.

Fixes: 98086df8b70c ("efi: add missed destroy_workqueue when efisubsys_init fails")
Cc: stable@vger.kernel.org
Cc: Li Heng <liheng40@huawei.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index f12cc29bd4b845603690442dc729728a80446dbc..033aac6be7daa6e1656da1ca95b9ac7ccdbcc24b 100644 (file)
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -374,8 +374,8 @@ static int __init efisubsys_init(void)
        efi_kobj = kobject_create_and_add("efi", firmware_kobj);
        if (!efi_kobj) {
                pr_err("efi: Firmware registration failed.\n");
-               destroy_workqueue(efi_rts_wq);
-               return -ENOMEM;
+               error = -ENOMEM;
+               goto err_destroy_wq;
        }
 
        if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
@@ -423,7 +423,10 @@ err_unregister:
                generic_ops_unregister();
 err_put:
        kobject_put(efi_kobj);
-       destroy_workqueue(efi_rts_wq);
+err_destroy_wq:
+       if (efi_rts_wq)
+               destroy_workqueue(efi_rts_wq);
+
        return error;
 }