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net: usb: lan78xx: Fix double free issue with interrupt buffer allocation

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In lan78xx_probe(), the buffer `buf` was being freed twice: once
implicitly through `usb_free_urb(dev->urb_intr)` with the
`URB_FREE_BUFFER` flag and again explicitly by `kfree(buf)`. This caused
a double free issue.

To resolve this, reordered `kmalloc()` and `usb_alloc_urb()` calls to
simplify the initialization sequence and removed the redundant
`kfree(buf)`.  Now, `buf` is allocated after `usb_alloc_urb()`, ensuring
it is correctly managed by  `usb_fill_int_urb()` and freed by
`usb_free_urb()` as intended.

Fixes: a6df95cae40b ("lan78xx: Fix memory allocation bug")
Cc: John Efstathiades <john.efstathiades@pebblebay.com>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20241116130558.1352230-1-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Oleksij Rempel 2024-11-16 14:05:57 +01:00 committed by Jakub Kicinski
parent f26a29a038
commit 03819abbeb
1 changed files with 15 additions and 16 deletions
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31
drivers/net/usb/lan78xx.c
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@ -4414,29 +4414,30 @@ static int lan78xx_probe(struct usb_interface *intf,
period = ep_intr->desc.bInterval;
maxp = usb_maxpacket(dev->udev, dev->pipe_intr);
buf = kmalloc(maxp, GFP_KERNEL);
if (!buf) {
ret = -ENOMEM;
goto out5;
}
dev->urb_intr = usb_alloc_urb(0, GFP_KERNEL);
if (!dev->urb_intr) {
ret = -ENOMEM;
goto out6;
} else {
usb_fill_int_urb(dev->urb_intr, dev->udev,
dev->pipe_intr, buf, maxp,
intr_complete, dev, period);
dev->urb_intr->transfer_flags |= URB_FREE_BUFFER;
goto out5;
}
buf = kmalloc(maxp, GFP_KERNEL);
if (!buf) {
ret = -ENOMEM;
goto free_urbs;
}
usb_fill_int_urb(dev->urb_intr, dev->udev,
dev->pipe_intr, buf, maxp,
intr_complete, dev, period);
dev->urb_intr->transfer_flags |= URB_FREE_BUFFER;
dev->maxpacket = usb_maxpacket(dev->udev, dev->pipe_out);
/* Reject broken descriptors. */
if (dev->maxpacket == 0) {
ret = -ENODEV;
goto out6;
goto free_urbs;
}
/* driver requires remote-wakeup capability during autosuspend. */
@ -4444,7 +4445,7 @@ static int lan78xx_probe(struct usb_interface *intf,
ret = lan78xx_phy_init(dev);
if (ret < 0)
goto out7;
goto free_urbs;
ret = register_netdev(netdev);
if (ret != 0) {
@ -4466,10 +4467,8 @@ static int lan78xx_probe(struct usb_interface *intf,
out8:
phy_disconnect(netdev->phydev);
out7:
free_urbs:
usb_free_urb(dev->urb_intr);
out6:
kfree(buf);
out5:
lan78xx_unbind(dev, intf);
out4: