bufio: panic in ReadSlice #4276
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At first I thought this was the wrapped io.Reader returning something suspicious that confused bufio, but I imagine this is just buggy concurrent access. Owner changed to @bradfitz. Status changed to Accepted. |
I have a case where I can reproduce this crash. In this case the caller of bufio.ReadSlice is the memcached package but it's a similar problem. I get an out of bounds error on line 260 of bufio.go. Right now I get the crash in a very large program under heavy load. Will attempt to isolate a small test case. |
I had a similar problem which was solved by https://code.google.com/p/go/source/detail?r=cd3ad8805953999b6de7de7b3f043bd6bd1b4e32 Check that n in that bufio method is not negative. |
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Owner changed to @davecheney. Status changed to WaitingForReply. |
I'm sorry, I meant this change https://code.google.com/p/go/source/detail?r=03a6b8c9c396b3de2c2c755362416b32ee875400. The root cause was a call to an io.Reader was returning the values -1, err, resulting in code like this http://play.golang.org/p/9CVH1WDGxo |
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This issue was closed by revision f0d9ccb. Status changed to Fixed. |
This issue was closed.
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Running an http stress program with lots of network timeouts, I saw this crash go by. Line 260 is: // Search new part of buffer if i := bytes.IndexByte(b.buf[n:b.w], delim); i >= 0 { panic: runtime error: slice bounds out of range goroutine 1 [running]: bufio.(*Reader).ReadSlice(0xf8403b9d20, 0x333100000000000a, 0x0, 0x0, 0x0, ...) /Users/bradfitz/go/src/pkg/bufio/bufio.go:260 +0x385 net/http.readLineBytes(0xf8403b9d20, 0x0, 0x0, 0x0, 0x0, ...) /Users/bradfitz/go/src/pkg/net/http/chunked.go:92 +0x50 net/http.readLine(0xf8403b9d20, 0x0, 0x0, 0x0, 0x0, ...) /Users/bradfitz/go/src/pkg/net/http/chunked.go:114 +0x49 net/http.(*chunkedReader).beginChunk(0xf8401bbe40, 0x1325c) /Users/bradfitz/go/src/pkg/net/http/chunked.go:47 +0x28 net/http.(*chunkedReader).Read(0xf8401bbe40, 0xf840086000, 0x2000, 0x2000, 0x1eda08, ...) /Users/bradfitz/go/src/pkg/net/http/chunked.go:65 +0x88 net/http.(*body).Read(0xf8401ff740, 0xf840086000, 0x2000, 0x2000, 0x30, ...) /Users/bradfitz/go/src/pkg/net/http/transfer.go:539 +0x8c io/ioutil.devNull.ReadFrom(0x0, 0xf8400bd7e0, 0xf8401ff740, 0x0, 0x0, ...) /Users/bradfitz/go/src/pkg/io/ioutil/ioutil.go:137 +0x8f io.Copy(0xf840071210, 0x0, 0xf8400bd7e0, 0xf8401ff740, 0x0, ...) /Users/bradfitz/go/src/pkg/io/io.go:352 +0xa2The text was updated successfully, but these errors were encountered: