[PATCH 6.6.y] Input: aiptek - validate raw macro indices before updating state

[PATCH 6.6.y] Input: aiptek - validate raw macro indices before updating state

[Miguel Garcia]

From: Pengpeng Hou <pengpeng@iscas.ac.cn>

aiptek_irq() derives macro key indices directly from tablet reports and
then uses them to index macroKeyEvents[]. Report types 4 and 5 also save
the derived value in aiptek->lastMacro and later use that state to
release the previous key.

Validate the raw macro index once before it enters that state machine, so
lastMacro only ever stores an in-range macro key. Keep direct bounds
checks for report type 6, which reads the macro number from the packet
body and uses it immediately.

Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Link: https://patch.msgid.link/20260329001711.88076-1-pengpeng@iscas.ac.cn
[dtor: fix macro fallback in report 5s to use -1]
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
(cherry picked from commit 95dffe32a66cbed07fbfa7afed39d56d5014e04f)
Signed-off-by: Miguel Garcia <miguelgarciaroman8@gmail.com>
---
 drivers/input/tablet/aiptek.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/input/tablet/aiptek.c b/drivers/input/tablet/aiptek.c
index baabc51547b83..6210cd99d6291 100644
--- a/drivers/input/tablet/aiptek.c
+++ b/drivers/input/tablet/aiptek.c
@@ -658,6 +658,8 @@ static void aiptek_irq(struct urb *urb)
 		pck = (data[1] & aiptek->curSetting.stylusButtonUpper) != 0 ? 1 : 0;
 
 		macro = dv && p && tip && !(data[3] & 1) ? (data[3] >> 1) : -1;
+		if (macro >= ARRAY_SIZE(macroKeyEvents))
+			macro = -1;
 		z = get_unaligned_le16(data + 4);
 
 		if (dv) {
@@ -699,7 +701,9 @@ static void aiptek_irq(struct urb *urb)
 		left = (data[1]& aiptek->curSetting.mouseButtonLeft) != 0 ? 1 : 0;
 		right = (data[1] & aiptek->curSetting.mouseButtonRight) != 0 ? 1 : 0;
 		middle = (data[1] & aiptek->curSetting.mouseButtonMiddle) != 0 ? 1 : 0;
-		macro = dv && p && left && !(data[3] & 1) ? (data[3] >> 1) : 0;
+		macro = dv && p && left && !(data[3] & 1) ? (data[3] >> 1) : -1;
+		if (macro >= ARRAY_SIZE(macroKeyEvents))
+			macro = -1;
 
 		if (dv) {
 		        /* If the selected tool changed, reset the old
@@ -737,11 +741,11 @@ static void aiptek_irq(struct urb *urb)
 	 */
 	else if (data[0] == 6) {
 		macro = get_unaligned_le16(data + 1);
-		if (macro > 0) {
+		if (macro > 0 && macro - 1 < ARRAY_SIZE(macroKeyEvents)) {
 			input_report_key(inputdev, macroKeyEvents[macro - 1],
 					 0);
 		}
-		if (macro < 25) {
+		if (macro + 1 < ARRAY_SIZE(macroKeyEvents)) {
 			input_report_key(inputdev, macroKeyEvents[macro + 1],
 					 0);
 		}
@@ -760,7 +764,8 @@ static void aiptek_irq(struct urb *urb)
 				aiptek->curSetting.toolMode;
 		}
 
-		input_report_key(inputdev, macroKeyEvents[macro], 1);
+		if (macro < ARRAY_SIZE(macroKeyEvents))
+			input_report_key(inputdev, macroKeyEvents[macro], 1);
 		input_report_abs(inputdev, ABS_MISC,
 				 1 | AIPTEK_REPORT_TOOL_UNKNOWN);
 		input_sync(inputdev);
-- 
2.43.0

Re: [PATCH 6.6.y] Input: aiptek - validate raw macro indices before updating state

[Greg KH]

On Mon, Sep 07, 2026 at 08:50:01PM +0200, Miguel Garcia wrote:
> From: Pengpeng Hou <pengpeng@iscas.ac.cn>
> 
> aiptek_irq() derives macro key indices directly from tablet reports and
> then uses them to index macroKeyEvents[]. Report types 4 and 5 also save
> the derived value in aiptek->lastMacro and later use that state to
> release the previous key.
> 
> Validate the raw macro index once before it enters that state machine, so
> lastMacro only ever stores an in-range macro key. Keep direct bounds
> checks for report type 6, which reads the macro number from the packet
> body and uses it immediately.
> 
> Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
> Link: https://patch.msgid.link/20260329001711.88076-1-pengpeng@iscas.ac.cn
> [dtor: fix macro fallback in report 5s to use -1]
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> (cherry picked from commit 95dffe32a66cbed07fbfa7afed39d56d5014e04f)
> Signed-off-by: Miguel Garcia <miguelgarciaroman8@gmail.com>
> ---
>  drivers/input/tablet/aiptek.c | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)

What about 6.12.y and 6.18.y?

thanks,

greg k-h

Re: [PATCH 6.6.y] Input: aiptek - validate raw macro indices before updating state

[Sasha Levin]

> aiptek_irq() derives macro key indices directly from tablet reports and
> then uses them to index macroKeyEvents[]. Report types 4 and 5 also save
> the derived value in aiptek->lastMacro and later use that state to
> release the previous key.

Queued for 6.6, thanks.

-- 
Thanks,
Sasha

Re: [PATCH 6.6.y] Input: aiptek - validate raw macro indices before updating state

[Miguel García Román]

Hi Greg,

You are right, 6.12.y and 6.18.y need the fix too. I missed those branches
in the initial submission. I am sending the two backports as follow-ups.

Both apply without code changes from upstream commit
95dffe32a66cbed07fbfa7afed39d56d5014e04f. I built
drivers/input/tablet/aiptek.o with W=1 on 6.12.109 and 6.18.50;
both builds passed without warnings.

Both patched kernels also booted under QEMU/KVM with UBSAN enabled
and passed 20 module load/unload cycles. This was a module lifecycle
smoke test, not a test of tablet reports or reproduction of the bug.

Thanks,
Miguel

[PATCH 6.12.y] Input: aiptek - validate raw macro indices before updating state

[Miguel García Román]

From: Pengpeng Hou <pengpeng@iscas.ac.cn>

commit 95dffe32a66cbed07fbfa7afed39d56d5014e04f upstream.

aiptek_irq() derives macro key indices directly from tablet reports and
then uses them to index macroKeyEvents[]. Report types 4 and 5 also save
the derived value in aiptek->lastMacro and later use that state to
release the previous key.

Validate the raw macro index once before it enters that state machine, so
lastMacro only ever stores an in-range macro key. Keep direct bounds
checks for report type 6, which reads the macro number from the packet
body and uses it immediately.

Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Link: https://patch.msgid.link/20260329001711.88076-1-pengpeng@iscas.ac.cn
[dtor: fix macro fallback in report 5s to use -1]
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Miguel Garcia <miguelgarciaroman8@gmail.com>
---
 drivers/input/tablet/aiptek.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/input/tablet/aiptek.c b/drivers/input/tablet/aiptek.c
index 2b3fbb0455d5c..9e78105bace77 100644
--- a/drivers/input/tablet/aiptek.c
+++ b/drivers/input/tablet/aiptek.c
@@ -658,6 +658,8 @@ static void aiptek_irq(struct urb *urb)
 		pck = (data[1] & aiptek->curSetting.stylusButtonUpper) != 0 ? 1 : 0;

 		macro = dv && p && tip && !(data[3] & 1) ? (data[3] >> 1) : -1;
+		if (macro >= ARRAY_SIZE(macroKeyEvents))
+			macro = -1;
 		z = get_unaligned_le16(data + 4);

 		if (dv) {
@@ -699,7 +701,9 @@ static void aiptek_irq(struct urb *urb)
 		left = (data[1]& aiptek->curSetting.mouseButtonLeft) != 0 ? 1 : 0;
 		right = (data[1] & aiptek->curSetting.mouseButtonRight) != 0 ? 1 : 0;
 		middle = (data[1] & aiptek->curSetting.mouseButtonMiddle) != 0 ? 1 : 0;
-		macro = dv && p && left && !(data[3] & 1) ? (data[3] >> 1) : 0;
+		macro = dv && p && left && !(data[3] & 1) ? (data[3] >> 1) : -1;
+		if (macro >= ARRAY_SIZE(macroKeyEvents))
+			macro = -1;

 		if (dv) {
 		        /* If the selected tool changed, reset the old
@@ -737,11 +741,11 @@ static void aiptek_irq(struct urb *urb)
 	 */
 	else if (data[0] == 6) {
 		macro = get_unaligned_le16(data + 1);
-		if (macro > 0) {
+		if (macro > 0 && macro - 1 < ARRAY_SIZE(macroKeyEvents)) {
 			input_report_key(inputdev, macroKeyEvents[macro - 1],
 					 0);
 		}
-		if (macro < 25) {
+		if (macro + 1 < ARRAY_SIZE(macroKeyEvents)) {
 			input_report_key(inputdev, macroKeyEvents[macro + 1],
 					 0);
 		}
@@ -760,7 +764,8 @@ static void aiptek_irq(struct urb *urb)
 				aiptek->curSetting.toolMode;
 		}

-		input_report_key(inputdev, macroKeyEvents[macro], 1);
+		if (macro < ARRAY_SIZE(macroKeyEvents))
+			input_report_key(inputdev, macroKeyEvents[macro], 1);
 		input_report_abs(inputdev, ABS_MISC,
 				 1 | AIPTEK_REPORT_TOOL_UNKNOWN);
 		input_sync(inputdev);
-- 
2.43.0

[PATCH 6.18.y] Input: aiptek - validate raw macro indices before updating state

[Miguel García Román]

From: Pengpeng Hou <pengpeng@iscas.ac.cn>

commit 95dffe32a66cbed07fbfa7afed39d56d5014e04f upstream.

aiptek_irq() derives macro key indices directly from tablet reports and
then uses them to index macroKeyEvents[]. Report types 4 and 5 also save
the derived value in aiptek->lastMacro and later use that state to
release the previous key.

Validate the raw macro index once before it enters that state machine, so
lastMacro only ever stores an in-range macro key. Keep direct bounds
checks for report type 6, which reads the macro number from the packet
body and uses it immediately.

Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Link: https://patch.msgid.link/20260329001711.88076-1-pengpeng@iscas.ac.cn
[dtor: fix macro fallback in report 5s to use -1]
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Miguel Garcia <miguelgarciaroman8@gmail.com>
---
 drivers/input/tablet/aiptek.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/input/tablet/aiptek.c b/drivers/input/tablet/aiptek.c
index 2b3fbb0455d5c..9e78105bace77 100644
--- a/drivers/input/tablet/aiptek.c
+++ b/drivers/input/tablet/aiptek.c
@@ -658,6 +658,8 @@ static void aiptek_irq(struct urb *urb)
 		pck = (data[1] & aiptek->curSetting.stylusButtonUpper) != 0 ? 1 : 0;

 		macro = dv && p && tip && !(data[3] & 1) ? (data[3] >> 1) : -1;
+		if (macro >= ARRAY_SIZE(macroKeyEvents))
+			macro = -1;
 		z = get_unaligned_le16(data + 4);

 		if (dv) {
@@ -699,7 +701,9 @@ static void aiptek_irq(struct urb *urb)
 		left = (data[1]& aiptek->curSetting.mouseButtonLeft) != 0 ? 1 : 0;
 		right = (data[1] & aiptek->curSetting.mouseButtonRight) != 0 ? 1 : 0;
 		middle = (data[1] & aiptek->curSetting.mouseButtonMiddle) != 0 ? 1 : 0;
-		macro = dv && p && left && !(data[3] & 1) ? (data[3] >> 1) : 0;
+		macro = dv && p && left && !(data[3] & 1) ? (data[3] >> 1) : -1;
+		if (macro >= ARRAY_SIZE(macroKeyEvents))
+			macro = -1;

 		if (dv) {
 		        /* If the selected tool changed, reset the old
@@ -737,11 +741,11 @@ static void aiptek_irq(struct urb *urb)
 	 */
 	else if (data[0] == 6) {
 		macro = get_unaligned_le16(data + 1);
-		if (macro > 0) {
+		if (macro > 0 && macro - 1 < ARRAY_SIZE(macroKeyEvents)) {
 			input_report_key(inputdev, macroKeyEvents[macro - 1],
 					 0);
 		}
-		if (macro < 25) {
+		if (macro + 1 < ARRAY_SIZE(macroKeyEvents)) {
 			input_report_key(inputdev, macroKeyEvents[macro + 1],
 					 0);
 		}
@@ -760,7 +764,8 @@ static void aiptek_irq(struct urb *urb)
 				aiptek->curSetting.toolMode;
 		}

-		input_report_key(inputdev, macroKeyEvents[macro], 1);
+		if (macro < ARRAY_SIZE(macroKeyEvents))
+			input_report_key(inputdev, macroKeyEvents[macro], 1);
 		input_report_abs(inputdev, ABS_MISC,
 				 1 | AIPTEK_REPORT_TOOL_UNKNOWN);
 		input_sync(inputdev);
-- 
2.43.0