Re: [PATCH net] ipv4: better IP_MAX_MTU enforcement

2017-08-16 Thread David Miller
From: Eric Dumazet Date: Wed, 16 Aug 2017 11:09:12 -0700 > From: Eric Dumazet > > While working on yet another syzkaller report, I found > that our IP_MAX_MTU enforcements were not properly done. > > gcc seems to reload dev->mtu for min(dev->mtu, IP_MAX_MTU), and > final result can be bigger t

[PATCH net] ipv4: better IP_MAX_MTU enforcement

2017-08-16 Thread Eric Dumazet
From: Eric Dumazet While working on yet another syzkaller report, I found that our IP_MAX_MTU enforcements were not properly done. gcc seems to reload dev->mtu for min(dev->mtu, IP_MAX_MTU), and final result can be bigger than IP_MAX_MTU :/ This is a problem because device mtu can be changed on