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From: Guanglei Zhu <zhugl3@xiaopeng.com>
To: dmitry.torokhov@gmail.com
Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
	liuc63@xiaopeng.com, stable@vger.kernel.org
Subject: [PATCH] Input: db9 - enlarge the Saturn multitap packet buffer
Date: Tue,  3 Nov 2026 16:41:31 +0800	[thread overview]
Message-ID: <20261103084135.426629-4-zhugl3@xiaopeng.com> (raw)
In-Reply-To: <20261103084135.426629-1-zhugl3@xiaopeng.com>

The Saturn multitap path fills the packet buffer block by block:

	for (i = 0; i < 60; i += 10) {
		data[i] = db9_saturn_read_analog(port, type, powered);
		if (data[i] != 0xff)
			/* read each pad */
			for (j = 0; j < (data[i] & 0x0f); j++)
				data[i + j + 1] = db9_saturn_read_analog(port, type, powered);
	}

Each block is ten bytes apart, and the low nibble of the block
header - taken from the device - allows up to fifteen more bytes,
so the last block can write up to data[65]. The buffer, however,
is sixty bytes, and the six bytes past it belong to the rest of
the stack frame.

Give the buffer the size the protocol layout actually requires.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Guanglei Zhu <zhugl3@xiaopeng.com>
---
 drivers/input/joystick/db9.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/input/joystick/db9.c b/drivers/input/joystick/db9.c
index e5d9b71aab99..73d1e7a296bb 100644
--- a/drivers/input/joystick/db9.c
+++ b/drivers/input/joystick/db9.c
@@ -253,7 +253,8 @@ static unsigned char db9_saturn_read_packet(struct parport *port, unsigned char
 /*
  * db9_saturn_report() analyzes packet and reports.
  */
-static int db9_saturn_report(unsigned char id, unsigned char data[60], struct input_dev *devs[], int n, int max_pads)
+static int db9_saturn_report(unsigned char id, unsigned char data[66],
+			      struct input_dev *devs[], int n, int max_pads)
 {
 	struct input_dev *dev;
 	int tmp, i, j;
@@ -321,7 +322,7 @@ static int db9_saturn_report(unsigned char id, unsigned char data[60], struct in
 
 static int db9_saturn(int mode, struct parport *port, struct input_dev *devs[])
 {
-	unsigned char id, data[60];
+	unsigned char id, data[66];
 	int type, n, max_pads;
 	int tmp, i;
 
-- 
2.50.1


  parent reply	other threads:[~2026-11-03  8:41 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-03  8:41 [PATCH] Input: joydev - avoid an undefined shift in the legacy 0x read Guanglei Zhu
2026-11-03  8:41 ` [PATCH] Input: joydev - avoid signed overflow in the broken-axis correction Guanglei Zhu
2026-11-03  8:55   ` [PATCH v2] " Guanglei Zhu
2026-11-03  8:41 ` [PATCH] Input: adi - bound the two-stream packet merge Guanglei Zhu
2026-11-03 11:17   ` [PATCH v2] " Guanglei Zhu
2026-11-03  8:41 ` Guanglei Zhu [this message]
2026-11-03  8:41 ` [PATCH] Input: lpc32xx-keys - reject matrices bigger than the hardware has Guanglei Zhu
2026-11-03  8:41 ` [PATCH] Input: mt6779-keypad - check the reported row and column Guanglei Zhu
2026-11-03  8:41 ` [PATCH] Input: tegra-kbc - check the pin numbers from the device tree Guanglei Zhu
2026-11-03  8:41 ` [PATCH] Input: cyapa_gen3 - clamp the reported finger count to the array Guanglei Zhu

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