Issues with
cancel func returned by context.WithCancel VET-V0011
Bug risk
Major
2 months ago
—
a year old
the cancel function is not used on all paths (possible context leak)
84 span.AddAttributes(trace.Int64Attribute("slot", int64(slot))) // lint:ignore uintcast -- This conversion is OK for tracing.
85
86 deadline := v.SlotDeadline(slot)
87 slotCtx, cancel := context.WithDeadline(ctx, deadline) 88 log := log.WithField("slot", slot)
89 log.WithField("deadline", deadline).Debug("Set deadline for proposals and attestations")
90this return statement may be reached without using the cancel var defined on line 87
76 span.End()
77 sub.Unsubscribe()
78 close(accountsChangedChan)
79 return // Exit if context is canceled. 80 case slot := <-v.NextSlot():
81 if !healthTracker.IsHealthy() {
82 continue
Description
The cancellation function returned by context.WithCancel, WithTimeout, and
WithDeadline must be called or the new context will remain live until its
parent context is cancelled. (The background context is never cancelled.)
This is usually an issue either because the variable was assigned to the blank identifier, or because there exists a control-flow path from the call to a return statement and that path does not "use" the cancel function.
For example, cancel is not used on all paths below, hence, is an issue.
func f(cond bool) {
var _, cancel = context.WithCancel(bg)
if cond {
x = cancel
}
}