From: Uwe Kleine-König Date: Wed, 10 Aug 2016 09:44:17 +0000 (+0200) Subject: net: ipconfig: fix use after free X-Git-Tag: v4.9-rc1~14^2~131 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=9c706a49d660;p=karo-tx-linux.git net: ipconfig: fix use after free ic_close_devs() calls kfree() for all devices's ic_device. Since commit 2647cffb2bc6 ("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: 2647cffb2bc6 ("net: ipconfig: Support using "delayed" DHCP replies") Reported-by: Geert Uytterhoeven Signed-off-by: Uwe Kleine-König Tested-by: Geert Uytterhoeven Signed-off-by: David S. Miller --- diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c index 42cf629357b5..66c2fe602810 100644 --- a/net/ipv4/ipconfig.c +++ b/net/ipv4/ipconfig.c @@ -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; }