fix(route): prevent use-after-close race on PacketConn in sniffing loop#4166
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hklcf wants to merge 1 commit into
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fix(route): prevent use-after-close race on PacketConn in sniffing loop#4166hklcf wants to merge 1 commit into
hklcf wants to merge 1 commit into
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When ctx is cancelled during packet sniffing, inputPacketConn.Close() is called while a goroutine may still be calling ReadPacket() and SetReadDeadline() on the same conn. Wait for the goroutine to finish after close to prevent concurrent access. Fixes SagerNet#4161
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Description
In
oute/route.go:709-768, the packet sniffing loop spawns a goroutine that calls \SetReadDeadline()\ and \ReadPacket()\ on \inputPacketConn. When \ctx.Done()\ fires, the main goroutine calls \inputPacketConn.Close()\ at line 728 while the goroutine may still be using the connection.
Fix
Wait for the goroutine to finish (<-done) after closing \inputPacketConn. Since \Close()\ unblocks \ReadPacket(), the goroutine will return quickly and the connection won't be used after close.
Related Issue
Fixes #4161