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ath10k: avoid possible string overflow

Message ID 20180328220635.3704458-1-arnd@arndb.de (mailing list archive)
State New, archived
Headers show

Commit Message

Arnd Bergmann March 28, 2018, 10:06 p.m. UTC
The way that 'strncat' is used here raised a warning in gcc-8:

drivers/net/wireless/ath/ath10k/wmi.c: In function 'ath10k_wmi_tpc_stats_final_disp_tables':
drivers/net/wireless/ath/ath10k/wmi.c:4649:4: error: 'strncat' output truncated before terminating nul copying as many bytes from a string as its length [-Werror=stringop-truncation]

Effectively, this is simply a strcat() but the use of strncat() suggests
some form of overflow check. Regardless of whether this might actually
overflow, using strlcat() instead of strncat() avoids the warning and
makes the code more robust.

Fixes: bc64d05220f3 ("ath10k: debugfs support to get final TPC stats for 10.4 variants")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/wireless/ath/ath10k/wmi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Kalle Valo April 10, 2018, 2:28 p.m. UTC | #1
Arnd Bergmann <arnd@arndb.de> wrote:

> The way that 'strncat' is used here raised a warning in gcc-8:
> 
> drivers/net/wireless/ath/ath10k/wmi.c: In function 'ath10k_wmi_tpc_stats_final_disp_tables':
> drivers/net/wireless/ath/ath10k/wmi.c:4649:4: error: 'strncat' output truncated before terminating nul copying as many bytes from a string as its length [-Werror=stringop-truncation]
> 
> Effectively, this is simply a strcat() but the use of strncat() suggests
> some form of overflow check. Regardless of whether this might actually
> overflow, using strlcat() instead of strncat() avoids the warning and
> makes the code more robust.
> 
> Fixes: bc64d05220f3 ("ath10k: debugfs support to get final TPC stats for 10.4 variants")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

Patch applied to ath-next branch of ath.git, thanks.

6707ba0105a2 ath10k: avoid possible string overflow
diff mbox

Patch

diff --git a/drivers/net/wireless/ath/ath10k/wmi.c b/drivers/net/wireless/ath/ath10k/wmi.c
index 9649bb752bbd..42522ed115f3 100644
--- a/drivers/net/wireless/ath/ath10k/wmi.c
+++ b/drivers/net/wireless/ath/ath10k/wmi.c
@@ -4309,7 +4309,7 @@  static void ath10k_tpc_config_disp_tables(struct ath10k *ar,
 							    rate_code[i],
 							    type);
 			snprintf(buff, sizeof(buff), "%8d ", tpc[j]);
-			strncat(tpc_value, buff, strlen(buff));
+			strlcat(tpc_value, buff, sizeof(tpc_value));
 		}
 		tpc_stats->tpc_table[type].pream_idx[i] = pream_idx;
 		tpc_stats->tpc_table[type].rate_code[i] = rate_code[i];
@@ -4646,7 +4646,7 @@  ath10k_wmi_tpc_stats_final_disp_tables(struct ath10k *ar,
 							       rate_code[i],
 							       type, pream_idx);
 			snprintf(buff, sizeof(buff), "%8d ", tpc[j]);
-			strncat(tpc_value, buff, strlen(buff));
+			strlcat(tpc_value, buff, sizeof(tpc_value));
 		}
 		tpc_stats->tpc_table_final[type].pream_idx[i] = pream_idx;
 		tpc_stats->tpc_table_final[type].rate_code[i] = rate_code[i];