Messages in this thread | | | From | (Eric W. Biederman) | Date | Fri, 07 Feb 2014 16:22:56 -0800 | Subject | Re: [PATCH] net: use __GFP_NORETRY for high order allocations |
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David Miller <davem@davemloft.net> writes:
> From: Eric Dumazet <eric.dumazet@gmail.com> > Date: Thu, 06 Feb 2014 10:42:42 -0800 > >> From: Eric Dumazet <edumazet@google.com> >> >> sock_alloc_send_pskb() & sk_page_frag_refill() >> have a loop trying high order allocations to prepare >> skb with low number of fragments as this increases performance. >> >> Problem is that under memory pressure/fragmentation, this can >> trigger OOM while the intent was only to try the high order >> allocations, then fallback to order-0 allocations. >> >> We had various reports from unexpected regressions. >> >> According to David, setting __GFP_NORETRY should be fine, >> as the asynchronous compaction is still enabled, and this >> will prevent OOM from kicking as in : > ... >> Signed-off-by: Eric Dumazet <edumazet@google.com> >> Acked-by: David Rientjes <rientjes@google.com> > > Applied, do we want this for -stable?
The first hunk goes back to 3.12 and the second hunk goes back to 3.8.
I think so. The change is safe and this class of problem can cause an external attack to trigger an OOM on your box, by controlling the packet flow.
Eric
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