Panic on reading request header

[lemonlinger]

The calling stack is below

panic: runtime error: slice bounds out of range [:4668] with capacity 4096
 goroutine 1755837666 [running]:
 bufio.(*Reader).Peek(0xc00cc283c0, 0x2ef)
 /usr/local/go/src/bufio/bufio.go:156 +0x191
 github.com/valyala/fasthttp.mustPeekBuffered(0xc00cc283c0)
 /root/go/pkg/mod/github.com/valyala/fasthttp@v1.38.0/header.go:3235 +0x25
 github.com/valyala/fasthttp.(*RequestHeader).tryRead(0xc00fd14c00, 0xc00cc283c0, 0x1)
 /root/go/pkg/mod/github.com/valyala/fasthttp@v1.38.0/header.go:2065 +0x2e5
 github.com/valyala/fasthttp.(*RequestHeader).readLoop(0xc064df9c38, 0xc00cc283c0, 0x1)
 /root/go/pkg/mod/github.com/valyala/fasthttp@v1.38.0/header.go:1971 +0x4d
 github.com/valyala/fasthttp.(*RequestHeader).Read(...)
 /root/go/pkg/mod/github.com/valyala/fasthttp@v1.38.0/header.go:1962
 github.com/valyala/fasthttp.(*Server).serveConn(0xc00102cd80, {0x17dafb8, 0xc064df9c38})
 /root/go/pkg/mod/github.com/valyala/fasthttp@v1.38.0/server.go:2186 +0x953
 github.com/valyala/fasthttp.(*workerPool).workerFunc(0xc002b32000, 0xc030f6dc20)
 /root/go/pkg/mod/github.com/valyala/fasthttp@v1.38.0/workerpool.go:224 +0xa9
 github.com/valyala/fasthttp.(*workerPool).getCh.func1()
 /root/go/pkg/mod/github.com/valyala/fasthttp@v1.38.0/workerpool.go:196 +0x38
 created by github.com/valyala/fasthttp.(*workerPool).getCh
 /root/go/pkg/mod/github.com/valyala/fasthttp@v1.38.0/workerpool.go:195 +0x1b5

But I can't reproduce this panic and got nothing about the request.

I use go1.17 and fasthttp@v1.38.0.

Any advice? Thanks.

[li-jin-gou]

My guess is that your asynchronous use of fasthttp's ctx or request is causing the problem. @lemonlinger

[lemonlinger]

My guess is that your asynchronous use of fasthttp's ctx or request is causing the problem. @lemonlinger

In my own code, I didn't use fasthttp context in an asynchronous way. But I did enable StreamRequestBody of fasthttp server. Is that probably related ?

[li-jin-gou]

My guess is that your asynchronous use of fasthttp's ctx or request is causing the problem. @lemonlinger

In my own code, I didn't use fasthttp context in an asynchronous way. But I did enable StreamRequestBody of fasthttp server. Is that probably related ?

Not sure, but you can try upgrading to the latest fasthttp to try it out.

[erikdubbelboer]

Please try the latest version of fasthttp. If it still happens can you share the code of your handler so we can see what is happening there?

[lemonlinger]

Will do. Thanks