ref: micro-optimise by reserving buffer size #803
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Before going into the loop we may as well make sure to reserve enough space for the entire buffer. Otherwise we could be allocating multiple times. This does not change the total allocated size.
| @@ -93,6 +93,7 @@ pub(crate) async fn read_lp( | |||
| }; | |||
| let mut reader = reader.take(size); | |||
| let size = usize::try_from(size).context("frame larger than usize")?; | |||
| buffer.reserve(size); | |||
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This should be limited, I can now easily attack your machine by putting a crazy value here, and causing an OOM
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My thinking was that I wasn't at all changing how much is being allocated, this attack already existed. To be fair I also faultily assumed MAX_MESSAGE_SIZE was already being respected while it obviously wasn't.
So fair shout, MAX_MESSAGE_SIZE wasn't being checked yet so may as well improve this.
dignifiedquire
approved these changes
Mar 1, 2023
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Before going into the loop we may as well make sure to reserve enough
space for the entire buffer. Otherwise we could be allocating
multiple times.
This does not change the total allocated size.