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GHSA-gmq2-39ff-f5qg

Published May 21, 2021·Last modified May 21, 2021

Affected Components(0)

No affected components available

Description

Impact

Processes using tableflip may encounter hung goroutines in the parent process, after a failed upgrade.

The Go runtime has annoying behaviour around setting and clearing O_NONBLOCK: exec.Cmd.Start() ends up calling os.File.Fd() for any file in exec.Cmd.ExtraFiles. os.File.Fd() disables both the use of the runtime poller for the file and clears O_NONBLOCK from the underlying open file descriptor.

This can lead to goroutines hanging in a parent process, after at least one failed upgrade. The bug manifests in goroutines which rely on either a deadline or interruption via Close() to be unblocked being stuck in read or accept like syscalls. As far as I can tell we've not experienced this problem in production, so it's most likely quite rare.

Patches

The problem has been fixed in v1.2.2.

Workarounds

None.

References

https://github.com/cloudflare/tableflip/commit/cae714b289e199db5da5f08af861ea65be6232c0

Risk Scores

Base Score

0.0

Measures severity based on intrinsic characteristics of the vulnerability, independent of environment.

Threat Intelligence

0.0

No exploitation activity has been observed at this time. Continue routine monitoring.

EPSS

N/A

Probability that this vulnerability will be exploited in the wild within the next 30 days.

Exploit

Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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