Redis Hot Patch (opens in new tab)

Yes. But the version I have posted is not particularly useful. It only targets OSX and there are probably not many OSX machines running Redis that are directly accessible on the internet. A lot of the code in the patcher is dedicated to parsing the Macho binary so there is a bit of effort in parsing ELF instead if you wanted to port it to Linux. Also, on Linux there are some protections (https://sourceware.org/glibc/wiki/PointerEncryption) around the longjump buffer that you need to break as well if you want a patcher that won't also kill the Redis instance.

There is a documented, reliable fix in everyone's hands, namely to shut down Redis and upgrade it. This is a cute hack with a chance of crashing everything.

One thing I learned from working at Ksplice was that the amount of effort needed to build reliable live patches was huge, way more than the amount of effort needed to build a live patch good enough for your average script kiddie, who often doesn't care about crashing one percent of machines, and definitely doesn't care about it just not working on 90% of machines. There is, unfortunately, an engineering imbalance between the difficulty of the good guys' and bad guys' goals. (This is why there was no truth to the claim that Ksplice was helping the bad guys build rootkits: the technical ability to build rootkits was there all along, since Ksplice was out of tree -- the innovative engineering in Ksplice was just making hot-patches reliable.)

I went with this fix on my linux servers: Upgrade redis.