Fix crash in timesync code #68
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When ConnectVSockSync fails in watchWakeupNotifications(), the returned net.Conn contains a nil value, but is not a nil interface (ie checking it for `== nil` returns false). This means we'll try to call `Close()` on the connection, which will cause a nil pointer dereference. See https://go.dev/doc/faq#nil_error and https://groups.google.com/g/golang-nuts/c/wnH302gBa4I for details about this behaviour. This bug is fixed by returning a nil interface when `vsockDevice.Connect(uint32(port))` returns an error.
praveenkumar
approved these changes
Nov 22, 2023
| // checking the return value for nil won't work as expected if we don't do this | ||
| return nil, err | ||
| } | ||
| return conn, nil |
|
/lgtm |
|
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When ConnectVSockSync fails in watchWakeupNotifications(), the returned
net.Conn contains a nil value, but is not a nil interface
(ie checking it for
== nilreturns false). This means we'll try to callClose()on the connection, which will cause a nil pointer dereference.See https://go.dev/doc/faq#nil_error and
https://groups.google.com/g/golang-nuts/c/wnH302gBa4I for details about
this behaviour.
This bug is fixed by returning a nil interface when
vsockDevice.Connect(uint32(port))returns an error.