Messages in this thread | | | Subject | Re: [PATCH] phonet: Check input from user before allocating | From | Eric Dumazet <> | Date | Tue, 03 Apr 2012 03:53:17 +0200 |
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On Mon, 2012-04-02 at 17:40 -0400, David Miller wrote: > From: "Rémi Denis-Courmont" <remi@remlab.net> > Date: Mon, 2 Apr 2012 22:01:40 +0300 > > > Le lundi 2 avril 2012 23:31:00 Sasha Levin, vous avez écrit : > >> A phonet packet is limited to USHRT_MAX bytes, this is never checked during > >> tx which means that the user can specify any size he wishes, and the kernel > >> will attempt to allocate that size. > > > > Does this really solve the problem? I guess 128kb is still possible with > > USHRT_MAX plus skbuff overhead, which might still trigger OOM relatively > > easily once the memory gets sufficiently fragmented. > > > > How does UDP deal with this? > > UDP generates a fragment list of MTU sized SKBs. > > Phonet could avoid the large allocations by building page based > SKBs.
Not that AF_UNIX does nothing in this respect, it can use order-XX pages for large datagrams.
(I beleve I sent a patch some time ago to address this point)
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