Messages in this thread | | | Date | Mon, 21 Jun 2021 17:28:38 +0200 | From | Greg KH <> | Subject | Re: [PATCH 4.19] inet: use bigger hash table for IP ID generation (backported to 4.19) |
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On Thu, Jun 17, 2021 at 01:19:18AM -0700, Amit Klein wrote: > Subject: inet: use bigger hash table for IP ID generation (backported to 4.19) > From: Amit Klein <aksecurity@gmail.com> > > This is a backport to 4.19 of the following patch, originally > developed by Eric Dumazet. > > In commit 73f156a6e8c1 ("inetpeer: get rid of ip_id_count") > I used a very small hash table that could be abused > by patient attackers to reveal sensitive information. > > Switch to a dynamic sizing, depending on RAM size. > > Typical big hosts will now use 128x more storage (2 MB) > to get a similar increase in security and reduction > of hash collisions. > > As a bonus, use of alloc_large_system_hash() spreads > allocated memory among all NUMA nodes. > > Fixes: 73f156a6e8c1 ("inetpeer: get rid of ip_id_count") > Reported-by: Amit Klein <aksecurity@gmail.com> > Cc: stable@vger.kernel.org > Cc: Eric Dumazet <edumazet@google.com> > Cc: Willy Tarreau <w@1wt.eu> > --- > net/ipv4/route.c | 42 ++++++++++++++++++++++++++++-------------- > 1 file changed, 28 insertions(+), 14 deletions(-) > > (limited to 'net/ipv4/route.c')
I had to dig up what the upstream git commit id was for this, please specify it next time :(
I've queued this, and the 4.14 version up. Can you create a 4.4.y and 4.9.y version as well?
thanks,
greg k-h
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