Patch "ath9k: fix buffer overrun for ar9287" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

ath9k: fix buffer overrun for ar9287

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:

     ath9k-fix-buffer-overrun-for-ar9287.patch

and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Arnd Bergmann <[email protected]>
Date: Mon, 14 Mar 2016 15:18:36 +0100
Subject: ath9k: fix buffer overrun for ar9287

From: Arnd Bergmann <[email protected]>

[ Upstream commit 83d6f1f15f8cce844b0a131cbc63e444620e48b5 ]

Code that was added back in 2.6.38 has an obvious overflow when accessing a static array, and at the time it was added only a code comment was put in front of it as a reminder to have it reviewed properly.

This has not happened, but gcc-6 now points to the specific overflow:

drivers/net/wireless/ath/ath9k/eeprom.c: In function 'ath9k_hw_get_gain_boundaries_pdadcs':
drivers/net/wireless/ath/ath9k/eeprom.c:483:44: error: array subscript is above array bounds [-Werror=array-bounds]

     maxPwrT4[i] = data_9287[idxL].pwrPdg[i][4];
                   ~~~~~~~~~~~~~~~~~~~~~~~~~^~~

It turns out that the correct array length exists in the local 'intercepts' variable of this function, so we can just use that instead of hardcoding '4', so this patch changes all three instances to use that variable. The other two instances were already correct, but it's more consistent this way.

---
 drivers/net/wireless/ath/ath9k/eeprom.c |    7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

@@ -403,10 +403,9 @@ void ath9k_hw_get_gain_boundaries_pdadcs
 
 	if (match) {
 		if (AR_SREV_9287(ah)) {
-			/* FIXME: array overrun? */
 			for (i = 0; i < numXpdGains; i++) {
 				minPwrT4[i] = data_9287[idxL].pwrPdg[i][0];
-				maxPwrT4[i] = data_9287[idxL].pwrPdg[i][4];
+				maxPwrT4[i] = data_9287[idxL].pwrPdg[i][intercepts - 1];
 				ath9k_hw_fill_vpd_table(minPwrT4[i], maxPwrT4[i],
 						data_9287[idxL].pwrPdg[i],
 						data_9287[idxL].vpdPdg[i],

@@ -416,7 +415,7 @@ void ath9k_hw_get_gain_boundaries_pdadcs
 		} else if (eeprom_4k) {
 			for (i = 0; i < numXpdGains; i++) {
 				minPwrT4[i] = data_4k[idxL].pwrPdg[i][0];
-				maxPwrT4[i] = data_4k[idxL].pwrPdg[i][4];
+				maxPwrT4[i] = data_4k[idxL].pwrPdg[i][intercepts - 1];
 				ath9k_hw_fill_vpd_table(minPwrT4[i], maxPwrT4[i],
 						data_4k[idxL].pwrPdg[i],
 						data_4k[idxL].vpdPdg[i],

@@ -426,7 +425,7 @@ void ath9k_hw_get_gain_boundaries_pdadcs
 		} else {
 			for (i = 0; i < numXpdGains; i++) {
 				minPwrT4[i] = data_def[idxL].pwrPdg[i][0];
-				maxPwrT4[i] = data_def[idxL].pwrPdg[i][4];
+				maxPwrT4[i] = data_def[idxL].pwrPdg[i][intercepts - 1];
 				ath9k_hw_fill_vpd_table(minPwrT4[i], maxPwrT4[i],
 						data_def[idxL].pwrPdg[i],
 						data_def[idxL].vpdPdg[i],

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/farsync-fix-off-by-one-bug-in-fst_add_one.patch queue-4.4/ath9k-fix-buffer-overrun-for-ar9287.patch queue-4.4/hwmon-max1111-return-enodev-from-max1111_read_channel-if-not-instantiated.patch queue-4.4/mlx4-add-missing-braces-in-verify_qp_parameters.patch