Make sure to always NUL-terminate file names retrieved from the firmware to avoid accessing data beyond the entry slab buffer and exposing it through sysfs in case the firmware data is corrupt.

Fixes: 75f3e8e47f38 ("firmware: introduce sysfs driver for QEMU's fw_cfg device") Cc: stable@vger.kernel.org # 4.6 Cc: Gabriel Somlo somlo@cmu.edu Signed-off-by: Johan Hovold johan@kernel.org --- drivers/firmware/qemu_fw_cfg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c index ccb7ed62452f..f08e056ed0ae 100644 --- a/drivers/firmware/qemu_fw_cfg.c +++ b/drivers/firmware/qemu_fw_cfg.c @@ -598,7 +598,7 @@ static int fw_cfg_register_file(const struct fw_cfg_file *f) /* set file entry information */ entry->size = be32_to_cpu(f->size); entry->select = be16_to_cpu(f->select); - memcpy(entry->name, f->name, FW_CFG_MAX_FILE_PATH); + strscpy(entry->name, f->name, FW_CFG_MAX_FILE_PATH);

/* register entry under "/sys/firmware/qemu_fw_cfg/by_key/" */ err = kobject_init_and_add(&entry->kobj, &fw_cfg_sysfs_entry_ktype,