From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCHv2 net] ipv4: reject RTNH_F_DEAD and RTNH_F_LINKDOWN
 from user space
Date: Mon, 11 Jul 2016 13:41:47 -0700 (PDT)
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From: Julian Anastasov <ja@ssi.bg>
Date: Sun, 10 Jul 2016 21:11:55 +0300

> Vegard Nossum is reporting for a crash in fib_dump_info
> when nh_dev = NULL and fib_nhs == 1:
 ...
> $ addr2line -e vmlinux -i 0x602b3d18
> include/linux/inetdevice.h:222
> net/ipv4/fib_semantics.c:1264
> 
> Problem happens when RTNH_F_LINKDOWN is provided from user space
> when creating routes that do not use the flag, catched with
> netlink fuzzer.
> 
> Currently, the kernel allows user space to set both flags
> to nh_flags and fib_flags but this is not intentional, the
> assumption was that they are not set. Fix this by rejecting
> both flags with EINVAL.
> 
> Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
> Fixes: 0eeb075fad73 ("net: ipv4 sysctl option to ignore routes when nexthop link is down")
> Signed-off-by: Julian Anastasov <ja@ssi.bg>

Applied and queud up for -stable, thanks Julian.