media: siano: Use scnprintf() for avoiding potential buffer overflow

Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit.  Fix it by replacing with scnprintf().

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/common/siano/smsdvb-debugfs.c b/drivers/media/common/siano/smsdvb-debugfs.c
index c95d458..8916bb6 100644 (file)
--- a/drivers/media/common/siano/smsdvb-debugfs.c
+++ b/drivers/media/common/siano/smsdvb-debugfs.c
@@ -45,88 +45,88 @@ static void smsdvb_print_dvb_stats(struct smsdvb_debugfs *debug_data,
 
        buf = debug_data->stats_data;
 
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "is_rf_locked = %d\n", p->is_rf_locked);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "is_demod_locked = %d\n", p->is_demod_locked);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "is_external_lna_on = %d\n", p->is_external_lna_on);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "SNR = %d\n", p->SNR);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "ber = %d\n", p->ber);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "FIB_CRC = %d\n", p->FIB_CRC);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "ts_per = %d\n", p->ts_per);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "MFER = %d\n", p->MFER);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "RSSI = %d\n", p->RSSI);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "in_band_pwr = %d\n", p->in_band_pwr);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "carrier_offset = %d\n", p->carrier_offset);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "modem_state = %d\n", p->modem_state);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "frequency = %d\n", p->frequency);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "bandwidth = %d\n", p->bandwidth);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "transmission_mode = %d\n", p->transmission_mode);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "modem_state = %d\n", p->modem_state);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "guard_interval = %d\n", p->guard_interval);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "code_rate = %d\n", p->code_rate);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "lp_code_rate = %d\n", p->lp_code_rate);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "hierarchy = %d\n", p->hierarchy);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "constellation = %d\n", p->constellation);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "burst_size = %d\n", p->burst_size);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "burst_duration = %d\n", p->burst_duration);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "burst_cycle_time = %d\n", p->burst_cycle_time);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "calc_burst_cycle_time = %d\n",
                      p->calc_burst_cycle_time);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "num_of_rows = %d\n", p->num_of_rows);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "num_of_padd_cols = %d\n", p->num_of_padd_cols);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "num_of_punct_cols = %d\n", p->num_of_punct_cols);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "error_ts_packets = %d\n", p->error_ts_packets);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "total_ts_packets = %d\n", p->total_ts_packets);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "num_of_valid_mpe_tlbs = %d\n", p->num_of_valid_mpe_tlbs);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "num_of_invalid_mpe_tlbs = %d\n", p->num_of_invalid_mpe_tlbs);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "num_of_corrected_mpe_tlbs = %d\n", p->num_of_corrected_mpe_tlbs);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "ber_error_count = %d\n", p->ber_error_count);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "ber_bit_count = %d\n", p->ber_bit_count);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "sms_to_host_tx_errors = %d\n", p->sms_to_host_tx_errors);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "pre_ber = %d\n", p->pre_ber);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "cell_id = %d\n", p->cell_id);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "dvbh_srv_ind_hp = %d\n", p->dvbh_srv_ind_hp);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "dvbh_srv_ind_lp = %d\n", p->dvbh_srv_ind_lp);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "num_mpe_received = %d\n", p->num_mpe_received);
 
        debug_data->stats_count = n;
@@ -148,42 +148,42 @@ static void smsdvb_print_isdb_stats(struct smsdvb_debugfs *debug_data,
 
        buf = debug_data->stats_data;
 
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "statistics_type = %d\t", p->statistics_type);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "full_size = %d\n", p->full_size);
 
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "is_rf_locked = %d\t\t", p->is_rf_locked);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "is_demod_locked = %d\t", p->is_demod_locked);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "is_external_lna_on = %d\n", p->is_external_lna_on);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "SNR = %d dB\t\t", p->SNR);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "RSSI = %d dBm\t\t", p->RSSI);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "in_band_pwr = %d dBm\n", p->in_band_pwr);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "carrier_offset = %d\t", p->carrier_offset);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "bandwidth = %d\t\t", p->bandwidth);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "frequency = %d Hz\n", p->frequency);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "transmission_mode = %d\t", p->transmission_mode);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "modem_state = %d\t\t", p->modem_state);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "guard_interval = %d\n", p->guard_interval);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "system_type = %d\t\t", p->system_type);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "partial_reception = %d\t", p->partial_reception);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "num_of_layers = %d\n", p->num_of_layers);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "sms_to_host_tx_errors = %d\n", p->sms_to_host_tx_errors);
 
        for (i = 0; i < 3; i++) {
@@ -191,31 +191,34 @@ static void smsdvb_print_isdb_stats(struct smsdvb_debugfs *debug_data,
                    p->layer_info[i].number_of_segments > 13)
                        continue;
 
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\nLayer %d\n", i);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\tcode_rate = %d\t",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "\nLayer %d\n", i);
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "\tcode_rate = %d\t",
                              p->layer_info[i].code_rate);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "constellation = %d\n",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "constellation = %d\n",
                              p->layer_info[i].constellation);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\tber = %-5d\t",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "\tber = %-5d\t",
                              p->layer_info[i].ber);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\tber_error_count = %-5d\t",
+               n += scnprintf(&buf[n], PAGE_SIZE - n,
+                             "\tber_error_count = %-5d\t",
                              p->layer_info[i].ber_error_count);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "ber_bit_count = %-5d\n",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "ber_bit_count = %-5d\n",
                              p->layer_info[i].ber_bit_count);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\tpre_ber = %-5d\t",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "\tpre_ber = %-5d\t",
                              p->layer_info[i].pre_ber);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\tts_per = %-5d\n",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "\tts_per = %-5d\n",
                              p->layer_info[i].ts_per);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\terror_ts_packets = %-5d\t",
+               n += scnprintf(&buf[n], PAGE_SIZE - n,
+                             "\terror_ts_packets = %-5d\t",
                              p->layer_info[i].error_ts_packets);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "total_ts_packets = %-5d\t",
+               n += scnprintf(&buf[n], PAGE_SIZE - n,
+                             "total_ts_packets = %-5d\t",
                              p->layer_info[i].total_ts_packets);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "ti_ldepth_i = %d\n",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "ti_ldepth_i = %d\n",
                              p->layer_info[i].ti_ldepth_i);
-               n += snprintf(&buf[n], PAGE_SIZE - n,
+               n += scnprintf(&buf[n], PAGE_SIZE - n,
                              "\tnumber_of_segments = %d\t",
                              p->layer_info[i].number_of_segments);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "tmcc_errors = %d\n",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "tmcc_errors = %d\n",
                              p->layer_info[i].tmcc_errors);
        }
 
@@ -238,44 +241,44 @@ static void smsdvb_print_isdb_stats_ex(struct smsdvb_debugfs *debug_data,
 
        buf = debug_data->stats_data;
 
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "statistics_type = %d\t", p->statistics_type);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "full_size = %d\n", p->full_size);
 
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "is_rf_locked = %d\t\t", p->is_rf_locked);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "is_demod_locked = %d\t", p->is_demod_locked);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "is_external_lna_on = %d\n", p->is_external_lna_on);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "SNR = %d dB\t\t", p->SNR);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "RSSI = %d dBm\t\t", p->RSSI);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "in_band_pwr = %d dBm\n", p->in_band_pwr);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "carrier_offset = %d\t", p->carrier_offset);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "bandwidth = %d\t\t", p->bandwidth);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "frequency = %d Hz\n", p->frequency);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "transmission_mode = %d\t", p->transmission_mode);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "modem_state = %d\t\t", p->modem_state);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "guard_interval = %d\n", p->guard_interval);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "system_type = %d\t\t", p->system_type);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "partial_reception = %d\t", p->partial_reception);
-       n += snprintf(&buf[n], PAGE_SIZE - n,
+       n += scnprintf(&buf[n], PAGE_SIZE - n,
                      "num_of_layers = %d\n", p->num_of_layers);
-       n += snprintf(&buf[n], PAGE_SIZE - n, "segment_number = %d\t",
+       n += scnprintf(&buf[n], PAGE_SIZE - n, "segment_number = %d\t",
                      p->segment_number);
-       n += snprintf(&buf[n], PAGE_SIZE - n, "tune_bw = %d\n",
+       n += scnprintf(&buf[n], PAGE_SIZE - n, "tune_bw = %d\n",
                      p->tune_bw);
 
        for (i = 0; i < 3; i++) {
@@ -283,31 +286,34 @@ static void smsdvb_print_isdb_stats_ex(struct smsdvb_debugfs *debug_data,
                    p->layer_info[i].number_of_segments > 13)
                        continue;
 
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\nLayer %d\n", i);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\tcode_rate = %d\t",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "\nLayer %d\n", i);
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "\tcode_rate = %d\t",
                              p->layer_info[i].code_rate);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "constellation = %d\n",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "constellation = %d\n",
                              p->layer_info[i].constellation);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\tber = %-5d\t",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "\tber = %-5d\t",
                              p->layer_info[i].ber);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\tber_error_count = %-5d\t",
+               n += scnprintf(&buf[n], PAGE_SIZE - n,
+                             "\tber_error_count = %-5d\t",
                              p->layer_info[i].ber_error_count);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "ber_bit_count = %-5d\n",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "ber_bit_count = %-5d\n",
                              p->layer_info[i].ber_bit_count);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\tpre_ber = %-5d\t",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "\tpre_ber = %-5d\t",
                              p->layer_info[i].pre_ber);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\tts_per = %-5d\n",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "\tts_per = %-5d\n",
                              p->layer_info[i].ts_per);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "\terror_ts_packets = %-5d\t",
+               n += scnprintf(&buf[n], PAGE_SIZE - n,
+                             "\terror_ts_packets = %-5d\t",
                              p->layer_info[i].error_ts_packets);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "total_ts_packets = %-5d\t",
+               n += scnprintf(&buf[n], PAGE_SIZE - n,
+                             "total_ts_packets = %-5d\t",
                              p->layer_info[i].total_ts_packets);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "ti_ldepth_i = %d\n",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "ti_ldepth_i = %d\n",
                              p->layer_info[i].ti_ldepth_i);
-               n += snprintf(&buf[n], PAGE_SIZE - n,
+               n += scnprintf(&buf[n], PAGE_SIZE - n,
                              "\tnumber_of_segments = %d\t",
                              p->layer_info[i].number_of_segments);
-               n += snprintf(&buf[n], PAGE_SIZE - n, "tmcc_errors = %d\n",
+               n += scnprintf(&buf[n], PAGE_SIZE - n, "tmcc_errors = %d\n",
                              p->layer_info[i].tmcc_errors);
        }