what happened

    github.com/gin-contrib/expvar v0.0.1
    github.com/gin-contrib/gzip v0.0.5
    github.com/gin-contrib/pprof v1.4.0
    github.com/gin-contrib/sessions v0.0.5
    github.com/gin-contrib/static v0.0.1
    github.com/gin-gonic/gin v1.8.1
    github.com/gin-contrib/sse v0.1.0 // indirect
    github.com/onsi/ginkgo v1.16.5 // indirect
    google.golang.org/appengine v1.6.7 // indirect

code

router.Use(func(c *gin.Context) {
        start := time.Now()
        if nil != c {
            c.Next()
        }
        end := time.Now()
        latency := end.Sub(start)

        fmt.Printf("%15s %3d %4s %15s %s\n", latency, c.Writer.Status(), c.Request.Method, c.ClientIP(), c.Request.URL.Path)
    })

2022/11/18 17:51:08 [Recovery] 2022/11/18 - 17:51:08 panic recovered:
runtime error: invalid memory address or nil pointer dereference
/usr/local/Cellar/go@1.18/1.18.6/libexec/src/runtime/panic.go:220 (0x403ac24)
        panicmem: panic(memoryError)
/usr/local/Cellar/go@1.18/1.18.6/libexec/src/runtime/signal_unix.go:818 (0x405353c)
        sigpanic: panicmem()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/context.go:173 (0x47f51d3)
        (*Context).Next: c.handlers[c.index](c)
/Users/51pwn/MyWork/goSqlite_gorm/pkg/server/sec.go:27 (0x5cebc67)
        InitSecRouter.func1: c.Next()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/context.go:173 (0x47f51dc)
        (*Context).Next: c.handlers[c.index](c)
/Users/51pwn/MyWork/goSqlite_gorm/pkg/brotlimd/handler.go:221 (0x5bd20ab)
        (*Handler).Gin: ctx.Next()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/context.go:173 (0x47f51dc)
        (*Context).Next: c.handlers[c.index](c)
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-contrib/gzip/handler.go:60 (0x5b63304)
        (*gzipHandler).Handle: c.Next()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/context.go:173 (0x47f51dc)
        (*Context).Next: c.handlers[c.index](c)
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-contrib/sessions/sessions.go:54 (0x5b6dd37)
        Sessions.func1: c.Next()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/context.go:173 (0x47f51dc)
        (*Context).Next: c.handlers[c.index](c)
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/logger.go:240 (0x4806e31)
        LoggerWithConfig.func1: c.Next()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/context.go:173 (0x47f51dc)
        (*Context).Next: c.handlers[c.index](c)
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/recovery.go:101 (0x4808477)
        CustomRecoveryWithWriter.func1: c.Next()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/context.go:173 (0x47f51dc)
        (*Context).Next: c.handlers[c.index](c)
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/gin.go:616 (0x4804a28)
        (*Engine).handleHTTPRequest: c.Next()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/gin.go:572 (0x48044fa)
        (*Engine).ServeHTTP: engine.handleHTTPRequest(c)
/Users/51pwn/MyWork/goSqlite_gorm/vendor/golang.org/x/net/http2/h2c/h2c.go:125 (0x47e3b5b)
        h2cHandler.ServeHTTP: s.Handler.ServeHTTP(w, r)
/usr/local/Cellar/go@1.18/1.18.6/libexec/src/net/http/server.go:2916 (0x44ac813)
        serverHandler.ServeHTTP: handler.ServeHTTP(rw, req)
/usr/local/Cellar/go@1.18/1.18.6/libexec/src/net/http/server.go:3523 (0x44af6f2)
        initALPNRequest.ServeHTTP: h.h.ServeHTTP(rw, req)
/usr/local/Cellar/go@1.18/1.18.6/libexec/src/net/http/h2_bundle.go:5907 (0x4467a27)
        (*http2serverConn).runHandler: handler(rw, req)
/usr/local/Cellar/go@1.18/1.18.6/libexec/src/runtime/asm_amd64.s:1571 (0x4071660)
        goexit: BYTE    $0x90   // NOP

Comment From: hktalent

Gin what happened? /github.com/gin-gonic/gin/context.go:173 (0x47f51d3) (*Context).Next: c.handlers[c.index](c)

Comment From: hktalent

It is recommended to perform nil judgment on the func passed in from use

Comment From: hktalent

Gin what happened? /github.com/gin-gonic/gin/context.go:173 (0x47f51d3) (*Context).Next: c.handlers[c.index](c) I found some uncertainties. Not every time I find a nil handler, the same exception occurs every time

Comment From: hktalent

2022/11/18 18:35:39 [Recovery] 2022/11/18 - 18:35:39 panic recovered:
runtime error: invalid memory address or nil pointer dereference
/usr/local/Cellar/go@1.18/1.18.6/libexec/src/runtime/panic.go:220 (0x403ad04)
        panicmem: panic(memoryError)
/usr/local/Cellar/go@1.18/1.18.6/libexec/src/runtime/signal_unix.go:818 (0x405361c)
        sigpanic: panicmem()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/context.go:173 (0x47f52b3)
        (*Context).Next: c.handlers[c.index](c)
/Users/51pwn/MyWork/goSqlite_gorm/pkg/brotlimd/handler.go:221 (0x5bd23cb)
        (*Handler).Gin: ctx.Next()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/context.go:173 (0x47f52bc)
        (*Context).Next: c.handlers[c.index](c)
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-contrib/gzip/handler.go:60 (0x5b63624)
        (*gzipHandler).Handle: c.Next()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/context.go:173 (0x47f52bc)
        (*Context).Next: c.handlers[c.index](c)
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-contrib/sessions/sessions.go:54 (0x5b6e057)
        Sessions.func1: c.Next()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/context.go:173 (0x47f52bc)
        (*Context).Next: c.handlers[c.index](c)
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/logger.go:240 (0x4806f11)
        LoggerWithConfig.func1: c.Next()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/context.go:173 (0x47f52bc)
        (*Context).Next: c.handlers[c.index](c)
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/recovery.go:101 (0x4808557)
        CustomRecoveryWithWriter.func1: c.Next()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/context.go:173 (0x47f52bc)
        (*Context).Next: c.handlers[c.index](c)
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/gin.go:616 (0x4804b08)
        (*Engine).handleHTTPRequest: c.Next()
/Users/51pwn/MyWork/goSqlite_gorm/vendor/github.com/gin-gonic/gin/gin.go:572 (0x48045da)
        (*Engine).ServeHTTP: engine.handleHTTPRequest(c)
/Users/51pwn/MyWork/goSqlite_gorm/vendor/golang.org/x/net/http2/h2c/h2c.go:125 (0x47e3c3b)
        h2cHandler.ServeHTTP: s.Handler.ServeHTTP(w, r)
/usr/local/Cellar/go@1.18/1.18.6/libexec/src/net/http/server.go:2916 (0x44ac8f3)
        serverHandler.ServeHTTP: handler.ServeHTTP(rw, req)
/usr/local/Cellar/go@1.18/1.18.6/libexec/src/net/http/server.go:3523 (0x44af7d2)
        initALPNRequest.ServeHTTP: h.h.ServeHTTP(rw, req)
/usr/local/Cellar/go@1.18/1.18.6/libexec/src/net/http/h2_bundle.go:5907 (0x4467b07)
        (*http2serverConn).runHandler: handler(rw, req)
/usr/local/Cellar/go@1.18/1.18.6/libexec/src/runtime/asm_amd64.s:1571 (0x4071740)
        goexit: BYTE    $0x90   // NOP

Comment From: hktalent

fix Gin what happened? /github.com/gin-gonic/gin/context.go:173 (0x47f51d3) (*Context).Next: c.handlers[c.index](c)

Comment From: hktalent

I checked all the codes, but I never found a place to inject a nil handler

It's amazing

Comment From: Cookiery

context.handlers comes from value.handlers (https://github.com/gin-gonic/gin/blob/master/gin.go#L614) value.handlers comes from node.handlers (https://github.com/gin-gonic/gin/blob/master/tree.go#L446) node.handlers was initialized in the func addRouter() https://github.com/gin-gonic/gin/blob/master/tree.go#L152 and the addRouter func is not concurrency-safe.

IDK if you use reset() Context or addRouter() concurrently.

You fix is LGTM.

I hope that would be useful for you!