[PATCH v3] HID: memory leak in dualshock4_get_calibration_data

[Eslam Khafagy <eslam.medhat1993@gmail.com>]

Function dualshock4_get_calibration_data allocates memory to pointer
buf .However, the function may exit prematurely due to transfer_failure
in this case it does not handle freeing memory.

This patch handles memory deallocation at exit.

Reported-by: syzbot+4f5f81e1456a1f645bf8@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/691560c4.a70a0220.3124cb.0019.GAE@google.com/T/
Tested-by: syzbot+4f5f81e1456a1f645bf8@syzkaller.appspotmail.com
Fixes: 947992c7fa9e0 ("HID: playstation: DS4: Fix calibration workaround for clone devices")
Cc: stable@vger.kernel.org
Signed-off-by: Eslam Khafagy <eslam.medhat1993@gmail.com>
---
v3:
* Address issues reported by checkpatch and re-format commit message
for better readability
* kfree() is safe so no need to check for NULL pointer

v2: https://lore.kernel.org/all/20251116022723.29857-1-eslam.medhat1993@gmail.com/
* Adding tag "Cc: stable@vger.kernel.org"

v1: https://lore.kernel.org/all/20251115022323.1395726-1-eslam.medhat1993@gmail.com/
 

 drivers/hid/hid-playstation.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c
index 128aa6abd10b..05a8522ace4f 100644
--- a/drivers/hid/hid-playstation.c
+++ b/drivers/hid/hid-playstation.c
@@ -1994,9 +1994,6 @@ static int dualshock4_get_calibration_data(struct dualshock4 *ds4)
 	acc_z_plus       = get_unaligned_le16(&buf[31]);
 	acc_z_minus      = get_unaligned_le16(&buf[33]);
 
-	/* Done parsing the buffer, so let's free it. */
-	kfree(buf);
-
 	/*
 	 * Set gyroscope calibration and normalization parameters.
 	 * Data values will be normalized to 1/DS4_GYRO_RES_PER_DEG_S degree/s.
@@ -2043,6 +2040,9 @@ static int dualshock4_get_calibration_data(struct dualshock4 *ds4)
 	ds4->accel_calib_data[2].sens_denom = range_2g;
 
 transfer_failed:
+	/* First free buf if still allocated */
+	kfree(buf);
+
 	/*
 	 * Sanity check gyro calibration data. This is needed to prevent crashes
 	 * during report handling of virtual, clone or broken devices not implementing
-- 
2.43.0