Fix a check, make a netflow padding function more safe.

Previously, `channelpadding_get_netflow_inactive_timeout_ms` would
crash with an assertion failure if `low_timeout` was greater than
`high_timeout`. That wasn't possible in practice because of checks
in `channelpadding_update_padding_for_channel`, but it's better not
to have a function whose correctness is this tricky to prove.

Fixes #40645.  Bugfix on 0.3.1.1-alpha.
This commit is contained in:
Nick Mathewson 2022-07-27 09:16:50 -04:00
parent 8d8afc4efa
commit 8e7bd96362
2 changed files with 6 additions and 1 deletions

5
changes/bug40645 Normal file
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@ -0,0 +1,5 @@
o Minor bugfixes (defense in depth):
- Change a test in the netflow padding code to make it more
_obviously_ safe against remotely triggered crashes.
(It was safe against these before, but not obviously so.)
Fixes bug 40645; bugfix on 0.3.1.1-alpha.

View File

@ -186,7 +186,7 @@ channelpadding_get_netflow_inactive_timeout_ms(const channel_t *chan)
high_timeout = MAX(high_timeout, chan->padding_timeout_high_ms);
}
if (low_timeout == high_timeout)
if (low_timeout >= high_timeout)
return low_timeout; // No randomization
/*