Commit 9c706a49 authored Aug 10, 2016 by Uwe Kleine-König Committed by David S. Miller Aug 10, 2016

net: ipconfig: fix use after free



ic_close_devs() calls kfree() for all devices's ic_device. Since commit
2647cffb ("net: ipconfig: Support using "delayed" DHCP replies")
the active device's ic_device is still used however to print the
ipconfig summary which results in an oops if the memory is already
changed. So delay freeing until after the autoconfig results are
reported.

Fixes: 2647cffb ("net: ipconfig: Support using "delayed" DHCP replies")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 0184165b

net/ipv4/ipconfig.c

+9 −8

Original line number	Diff line number	Diff line
		@@ -1492,14 +1492,6 @@ static int __init ip_auto_config(void)
		if (ic_defaults() < 0)
		return -1;

		/*
		* Close all network devices except the device we've
		* autoconfigured and set up routes.
		*/
		ic_close_devs();
		if (ic_setup_if() < 0 \|\| ic_setup_routes() < 0)
		return -1;

		/*
		* Record which protocol was actually used.
		*/
		@@ -1534,6 +1526,15 @@ static int __init ip_auto_config(void)
		pr_cont("\n");
		#endif /* !SILENT */

		/*
		* Close all network devices except the device we've
		* autoconfigured and set up routes.
		*/
		ic_close_devs();
		if (ic_setup_if() < 0 \|\| ic_setup_routes() < 0)
		return -1;


		return 0;
		}

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