wgengine/netlog: fix nil pointer dereference in logtail #8598
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When `Logger.Startup` is called and a new `http.Client` is initialized for logtail, `nl.logger` is nil. It's initialized right after creating the `http.Client`. But because we're passing a method value, it actually works and passes the value with a `nil` receiver. Later, when `logtail.Logger.Logf` is called from the `http.Client`, `tailscaled` panics when trying to access the fields of that nil logger. Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
andrew-d
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Jul 13, 2023
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Very good catch, thank you 🤦 Optional, but if you feel like it... we could pull out the log.Printf from the call to logtail.NewLogger into a shared variable between that function and logpolicy.NewLogtailTransport. We can always do that later after this fix though 😄
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
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@andrew-d updated, is this what you meant? |
alexelisenko
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Feb 15, 2024
Signed-off-by: Alex Paguis <alex@windscribe.com>
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When
Logger.Startupis called and a newhttp.Clientis initialized for logtail,nl.loggeris nil. It's initialized right after creating thehttp.Client. But because we're passing a method value, it actually works and passes the value with anilreceiver.Later, when
logtail.Logger.Logfis called from thehttp.Client,tailscaledpanics when trying to access the fields of that nil logger.