[PATCH] Input: joydev - prevent potential read overflow in ioctl
From: Dan Carpenter <hidden>
Date: 2021-02-17 06:11:44
Also in:
kernel-janitors
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Dmitry Torokhov, Linus Torvalds
The problem here is that "len" might be less than "joydev->nabs" so the
loops which verfy abspam[i] and keypam[] might read beyond the buffer.
Fixes: 999b874f4aa3 ("Input: joydev - validate axis/button maps before clobbering current ones")
Signed-off-by: Dan Carpenter <redacted>
---
drivers/input/joydev.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/input/joydev.c b/drivers/input/joydev.c
index a2b5fbba2d3b..750f4513fe20 100644
--- a/drivers/input/joydev.c
+++ b/drivers/input/joydev.c@@ -456,7 +456,7 @@ static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev, if (IS_ERR(abspam)) return PTR_ERR(abspam); - for (i = 0; i < joydev->nabs; i++) { + for (i = 0; i < len && i < joydev->nabs; i++) { if (abspam[i] > ABS_MAX) { retval = -EINVAL; goto out;
@@ -487,7 +487,7 @@ static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev, if (IS_ERR(keypam)) return PTR_ERR(keypam); - for (i = 0; i < joydev->nkey; i++) { + for (i = 0; i < (len / 2) && i < joydev->nkey; i++) { if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) { retval = -EINVAL; goto out;
--
2.30.0