net/http or io: panic (reduced test case included) #7848
Labels
Comments
This issue was closed.
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
What does 'go version' print? o version go1.2 darwin/amd64 server.go: package main import ( "io" "net/http" ) func main() { http.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) { io.WriteString(w, "Hello World\n") }) http.ListenAndServe(":8100", nil) } crashproxy.go: package main import ( "net/http" "net/http/httputil" "net/url" ) func main() { server, _ := url.Parse("http://127.0.0.1:8100";) http.Handle("/", httputil.NewSingleHostReverseProxy(server)) http.ListenAndServe(":11111", nil) } % go run server.go & % go build crashproxy.go # we need the executable below % ./crashproxy With these running, we'll POST a file to the hello server through the reverse proxy. We'll send the crashproxy binary (5-10 MBs). % curl -i -F "file=@crashproxy;filename=crashproxy" http://localhost:11111 Run that curl command a number of times (drum arrow-up / enter quickly) until crashproxy panics. I believe the crash is unrelated to the reverse proxy code but it was easier to demonstrate using it. [My real-world code that triggered this panic had a (node.js) server process that sometimes crashed (upon file POST) and then sometimes took a (golang) reverse proxy with it. This test case doesn't feature a crashing server process because one that just responded directly seemed to do the trick as well] Panic log follows: panic: runtime error: invalid memory address or nil pointer dereference [signal 0xb code=0x1 addr=0x20 pc=0x518c0] goroutine 40 [running]: runtime.panic(0x1f8d60, 0x476df9) /usr/local/go/src/pkg/runtime/panic.c:266 +0xb6 bufio.(*Reader).Read(0xc210037660, 0xc2100ca000, 0x1000, 0x1000, 0x1000, ...) /usr/local/go/src/pkg/bufio/bufio.go:152 +0x100 io.(*LimitedReader).Read(0xc2100a8ee0, 0xc2100ca000, 0x1000, 0x1000, 0x1000, ...) /usr/local/go/src/pkg/io/io.go:398 +0xbb net/http.(*body).Read(0xc2100c7030, 0xc2100ca000, 0x1000, 0x1000, 0x1000, ...) /usr/local/go/src/pkg/net/http/transfer.go:534 +0x96 net/http.(*expectContinueReader).Read(0xc2100a8f00, 0xc2100ca000, 0x1000, 0x1000, 0xc2100ca000, ...) /usr/local/go/src/pkg/net/http/server.go:520 +0x11a io.(*LimitedReader).Read(0xc2100a8060, 0xc2100ca000, 0x1000, 0x1000, 0xbf, ...) /usr/local/go/src/pkg/io/io.go:398 +0xbb bufio.(*Writer).ReadFrom(0xc21004e4c0, 0x55f458, 0xc2100a8060, 0xa6ed1, 0x0, ...) /usr/local/go/src/pkg/bufio/bufio.go:622 +0x15a io.Copy(0x55f588, 0xc21004e4c0, 0x55f458, 0xc2100a8060, 0x0, ...) /usr/local/go/src/pkg/io/io.go:348 +0x124 net/http.(*transferWriter).WriteBody(0xc2100c62a0, 0x55f588, 0xc21004e4c0, 0x0, 0x0) /usr/local/go/src/pkg/net/http/transfer.go:196 +0x57c net/http.(*Request).write(0xc2100361a0, 0x55f588, 0xc21004e4c0, 0x0, 0xc2100c7150, ...) /usr/local/go/src/pkg/net/http/request.go:400 +0x7e4 net/http.(*persistConn).writeLoop(0xc210058780) /usr/local/go/src/pkg/net/http/transport.go:797 +0x185 created by net/http.(*Transport).dialConn /usr/local/go/src/pkg/net/http/transport.go:529 +0x61e goroutine 1 [IO wait]: net.runtime_pollWait(0x55f300, 0x72, 0x0) /private/tmp/bindist142506725/go/src/pkg/runtime/netpoll.goc:116 +0x6a net.(*pollDesc).Wait(0xc21004f140, 0x72, 0x55e098, 0x23) /usr/local/go/src/pkg/net/fd_poll_runtime.go:81 +0x34 net.(*pollDesc).WaitRead(0xc21004f140, 0x23, 0x55e098) /usr/local/go/src/pkg/net/fd_poll_runtime.go:86 +0x30 net.(*netFD).accept(0xc21004f0e0, 0x2a8fb8, 0x0, 0x55e098, 0x23) /usr/local/go/src/pkg/net/fd_unix.go:382 +0x2c2 net.(*TCPListener).AcceptTCP(0xc2100001e0, 0x3760b, 0x59ee10, 0x3760b) /usr/local/go/src/pkg/net/tcpsock_posix.go:233 +0x47 net.(*TCPListener).Accept(0xc2100001e0, 0x55f3a8, 0xc210000aa0, 0xc210058580, 0x0) /usr/local/go/src/pkg/net/tcpsock_posix.go:243 +0x27 net/http.(*Server).Serve(0xc21001e410, 0x55e360, 0xc2100001e0, 0x0, 0x0) /usr/local/go/src/pkg/net/http/server.go:1622 +0x91 net/http.(*Server).ListenAndServe(0xc21001e410, 0xc21001e410, 0xc21004b4a0) /usr/local/go/src/pkg/net/http/server.go:1612 +0xa0 net/http.ListenAndServe(0x237c00, 0x6, 0x0, 0x0, 0x0, ...) /usr/local/go/src/pkg/net/http/server.go:1677 +0x6d main.main() /Users/olov/projects/mcs/goproxy/src/crashproxy.go:12 +0xad goroutine 3 [IO wait]: net.runtime_pollWait(0x55f258, 0x72, 0x0) /private/tmp/bindist142506725/go/src/pkg/runtime/netpoll.goc:116 +0x6a net.(*pollDesc).Wait(0xc21004f300, 0x72, 0x55e098, 0x23) /usr/local/go/src/pkg/net/fd_poll_runtime.go:81 +0x34 net.(*pollDesc).WaitRead(0xc21004f300, 0x23, 0x55e098) /usr/local/go/src/pkg/net/fd_poll_runtime.go:86 +0x30 net.(*netFD).Read(0xc21004f2a0, 0xc21005a000, 0x1000, 0x1000, 0x0, ...) /usr/local/go/src/pkg/net/fd_unix.go:204 +0x2a0 net.(*conn).Read(0xc210000200, 0xc21005a000, 0x1000, 0x1000, 0x0, ...) /usr/local/go/src/pkg/net/net.go:122 +0xc5 net/http.(*liveSwitchReader).Read(0xc2100582a8, 0xc21005a000, 0x1000, 0x1000, 0x5bab48, ...) /usr/local/go/src/pkg/net/http/server.go:204 +0xa5 io.(*LimitedReader).Read(0xc21004b4e0, 0xc21005a000, 0x1000, 0x1000, 0xb434, ...) /usr/local/go/src/pkg/io/io.go:398 +0xbb bufio.(*Reader).fill(0xc2100370c0) /usr/local/go/src/pkg/bufio/bufio.go:91 +0x110 bufio.(*Reader).ReadSlice(0xc2100370c0, 0xa, 0x0, 0x0, 0x0, ...) /usr/local/go/src/pkg/bufio/bufio.go:274 +0x204 bufio.(*Reader).ReadLine(0xc2100370c0, 0x0, 0x0, 0x0, 0x0, ...) /usr/local/go/src/pkg/bufio/bufio.go:305 +0x63 net/textproto.(*Reader).readLineSlice(0xc21001da50, 0x555000, 0x199fe0, 0x5bace8, 0x20752, ...) /usr/local/go/src/pkg/net/textproto/reader.go:55 +0x61 net/textproto.(*Reader).ReadLine(0xc21001da50, 0xc2100441a0, 0x0, 0xc21005b000, 0x0) /usr/local/go/src/pkg/net/textproto/reader.go:36 +0x27 net/http.ReadRequest(0xc2100370c0, 0xc2100441a0, 0x0, 0x0) /usr/local/go/src/pkg/net/http/request.go:526 +0x88 net/http.(*conn).readRequest(0xc210058280, 0x0, 0x0, 0x0) /usr/local/go/src/pkg/net/http/server.go:575 +0x1bb net/http.(*conn).serve(0xc210058280) /usr/local/go/src/pkg/net/http/server.go:1123 +0x3b4 created by net/http.(*Server).Serve /usr/local/go/src/pkg/net/http/server.go:1644 +0x28b goroutine 33 [sleep]: time.Sleep(0x1dcd6500) /private/tmp/bindist142506725/go/src/pkg/runtime/time.goc:31 +0x31 net/http.(*conn).closeWriteAndWait(0xc210058480) /usr/local/go/src/pkg/net/http/server.go:1072 +0x75 net/http.(*conn).serve(0xc210058480) /usr/local/go/src/pkg/net/http/server.go:1174 +0x81d created by net/http.(*Server).Serve /usr/local/go/src/pkg/net/http/server.go:1644 +0x28b goroutine 37 [sleep]: time.Sleep(0x1dcd6500) /private/tmp/bindist142506725/go/src/pkg/runtime/time.goc:31 +0x31 net/http.(*conn).closeWriteAndWait(0xc210058580) /usr/local/go/src/pkg/net/http/server.go:1072 +0x75 net/http.(*conn).serve(0xc210058580) /usr/local/go/src/pkg/net/http/server.go:1174 +0x81d created by net/http.(*Server).Serve /usr/local/go/src/pkg/net/http/server.go:1644 +0x28b exit status 2The text was updated successfully, but these errors were encountered: