Commit 1ae292a2 authored Aug 22, 2016 by Geert Uytterhoeven Committed by David S. Miller Aug 22, 2016

net: ipconfig: Fix NULL pointer dereference on RARP/BOOTP/DHCP timeout



If no RARP, BOOTP, or DHCP response is received, ic_dev is never set,
causing a NULL pointer dereference in ic_close_devs():

    Sending DHCP requests ...... timed out!
    Unable to handle kernel NULL pointer dereference at virtual address 00000004

To fix this, add a check to avoid dereferencing ic_dev if it is still
NULL.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Fixes: 2647cffb ("net: ipconfig: Support using "delayed" DHCP replies")
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 8b7ac60a

net/ipv4/ipconfig.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -306,7 +306,7 @@ static void __init ic_close_devs(void)
		while ((d = next)) {
		next = d->next;
		dev = d->dev;
		if (dev != ic_dev->dev && !netdev_uses_dsa(dev)) {
		if ((!ic_dev \|\| dev != ic_dev->dev) && !netdev_uses_dsa(dev)) {
		pr_debug("IP-Config: Downing %s\n", dev->name);
		dev_change_flags(dev, d->flags);
		}

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