Commit 5b21e3c7 authored Oct 06, 2015 by Javier Martinez Canillas Committed by Dmitry Torokhov Oct 06, 2015

Input: joydev - fix possible ERR_PTR() dereferencing



Commit 5702222c ("Input: joydev - use memdup_user() to duplicate
memory from user-space") changed the kmalloc() and copy_from_user()
with a single call to memdup_user() but wrongly used the same error
path than the old code in which the buffer allocated by kmalloc() was
freed if copy_from_user() failed.

This is of course wrong since if memdup_user() fails, no memory was
allocated and the error in the error-valued pointer should be returned.

Fixes: 5702222c ("Input: joydev - use memdup_user() to duplicate
memory from user-space")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

parent c7efd123

drivers/input/joydev.c

+4 −8

Original line number	Diff line number	Diff line
		@@ -445,10 +445,8 @@ static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev,

		/* Validate the map. */
		abspam = memdup_user(argp, len);
		if (IS_ERR(abspam)) {
		retval = PTR_ERR(abspam);
		goto out;
		}
		if (IS_ERR(abspam))
		return PTR_ERR(abspam);

		for (i = 0; i < joydev->nabs; i++) {
		if (abspam[i] > ABS_MAX) {
		@@ -478,10 +476,8 @@ static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,

		/* Validate the map. */
		keypam = memdup_user(argp, len);
		if (IS_ERR(keypam)) {
		retval = PTR_ERR(keypam);
		goto out;
		}
		if (IS_ERR(keypam))
		return PTR_ERR(keypam);

		for (i = 0; i < joydev->nkey; i++) {
		if (keypam[i] > KEY_MAX \|\| keypam[i] < BTN_MISC) {

Admin message