4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> commit 251fe09f13bfb54c1ede66ee8bf8ddd0061c4f7c upstream. This is a static analysis fix. The warning is: drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c:912 iwl_mvm_fw_dbg_collect() warn: integer overflows 'sizeof(*desc) + len' I guess this code is supposed to take a NUL character, but if we write zero bytes then it tries to write -1 characters and crashes. Fixes: c91b865cb14d ("iwlwifi: mvm: support description for user triggered fw dbg collection") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireless/intel/iwlwifi/mvm/debugfs.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/net/wireless/intel/iwlwifi/mvm/debugfs.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/debugfs.c @@ -1056,6 +1056,8 @@ static ssize_t iwl_dbgfs_fw_dbg_collect_ if (ret) return ret; + if (count == 0) + return 0; iwl_mvm_fw_dbg_collect(mvm, FW_DBG_TRIGGER_USER, buf, (count - 1), NULL);