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crypto/sha1: out-of-bounds access in blockAVX2 #15617

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dvyukov opened this issue May 9, 2016 · 4 comments
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crypto/sha1: out-of-bounds access in blockAVX2 #15617

dvyukov opened this issue May 9, 2016 · 4 comments
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Go1.7

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@dvyukov
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dvyukov commented May 9, 2016

go version devel +149ac34 Mon May 9 17:50:29 2016 +0000 linux/amd64

unexpected fault address 0x7f736efbf000
fatal error: fault
[signal SIGSEGV: segmentation violation code=0x2 addr=0x7f736efbf000 pc=0x44b655]

goroutine 1 [running]:
runtime.throw(0x46a144, 0x5)
    src/runtime/panic.go:566 +0x8b fp=0xc4200797e0 sp=0xc4200797c8
runtime.sigpanic()
    src/runtime/sigpanic_unix.go:27 +0x27e fp=0xc420079830 sp=0xc4200797e0
crypto/sha1.blockAVX2(0xc420079e70, 0x7f736efbef00, 0x100, 0x1100)
    src/crypto/sha1/sha1block_amd64.s:1458 +0x4e5 fp=0xc420079db8 sp=0xc420079830
crypto/sha1.block(0xc420079e70, 0x7f736efbef00, 0x100, 0x1100)
    src/crypto/sha1/sha1block_amd64.go:19 +0x7e fp=0xc420079de0 sp=0xc420079db8
crypto/sha1.(*digest).Write(0xc420079e70, 0x7f736efbef00, 0x100, 0x1100, 0x3, 0xc4200001a0, 0x4226fa)
    src/crypto/sha1/sha1.go:75 +0x116 fp=0xc420079e20 sp=0xc420079de0
crypto/sha1.Sum(0x7f736efbef00, 0x100, 0x1100, 0x0, 0x0, 0x0)
    src/crypto/sha1/sha1.go:128 +0xcc fp=0xc420079ee0 sp=0xc420079e20
main.main()
    /tmp/sha1.go:19 +0x15b fp=0xc420079f50 sp=0xc420079ee0
runtime.main()
    src/runtime/proc.go:189 +0x20a fp=0xc420079fa0 sp=0xc420079f50
runtime.goexit()
    src/runtime/asm_amd64.s:2058 +0x1 fp=0xc420079fa8 sp=0xc420079fa0

package main

import (
    "crypto/sha1"
    "syscall"
)

func main() {
    const pageSize = 4 << 10
    data, err := syscall.Mmap(0, 0, 2*pageSize, syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_ANON|syscall.MAP_PRIVATE)
    if err != nil {
        panic(err)
    }
    if err := syscall.Mprotect(data[pageSize:], syscall.PROT_NONE); err != nil {
        panic(err)
    }
    for i := 0; i < pageSize; i++ {
        println(i)
        sha1.Sum(data[pageSize-i : pageSize])
    }
}

One does not simply write native code.
@dvyukov dvyukov added this to the Go1.7 milestone May 9, 2016
@bradfitz
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bradfitz commented May 9, 2016

I assume this is a regression introduced by fafadc5. @TocarIP, can you take a look?

@bradfitz bradfitz changed the title crypto/sha1: out-of-bounds access crypto/sha1: out-of-bounds access in blockAVX2 May 10, 2016
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I just hit this in a non-contrived program as well:

bradfitz@dev-bradfitz-debian2:~/go$ gomote push user-bradfitz-plan9-386-0
unexpected fault address 0xc420700000
fatal error: fault
[signal SIGSEGV: segmentation violation code=0x1 addr=0xc420700000 pc=0x4a61d5]

goroutine 1 [running]:
runtime.throw(0x69d887, 0x5)
        /home/bradfitz/go/src/runtime/panic.go:566 +0x8b fp=0xc42004cc60 sp=0xc42004cc48
runtime.sigpanic()
        /home/bradfitz/go/src/runtime/sigpanic_unix.go:27 +0x27e fp=0xc42004ccb0 sp=0xc42004cc60
crypto/sha1.blockAVX2(0xc4200571f0, 0xc4206f8000, 0x8000, 0x8000)
        /home/bradfitz/go/src/crypto/sha1/sha1block_amd64.s:1458 +0x4e5 fp=0xc42004d238 sp=0xc42004ccb0
crypto/sha1.block(0xc4200571f0, 0xc4206f8000, 0x8000, 0x8000)
        /home/bradfitz/go/src/crypto/sha1/sha1block_amd64.go:19 +0x7e fp=0xc42004d260 sp=0xc42004d238
crypto/sha1.(*digest).Write(0xc4200571f0, 0xc4206f8000, 0x8000, 0x8000, 0x8000, 0x0, 0x0)
        /home/bradfitz/go/src/crypto/sha1/sha1.go:75 +0x116 fp=0xc42004d2a0 sp=0xc42004d260
io.copyBuffer(0x7f8eb7b403e0, 0xc4200571f0, 0x7b7320, 0xc42002a188, 0xc4206f8000, 0x8000, 0x8000, 0x66dc00, 0xc42004d300, 0x7f8eb7b403e0)
        /home/bradfitz/go/src/io/io.go:400 +0x24c fp=0xc42004d320 sp=0xc42004d2a0
io.Copy(0x7f8eb7b403e0, 0xc4200571f0, 0x7b7320, 0xc42002a188, 0xc4200571f0, 0xc4203dd2d8, 0x406162)
        /home/bradfitz/go/src/io/io.go:368 +0x5a fp=0xc42004d378 sp=0xc42004d320
main.fileSHA1(0xc420120d00, 0x35, 0x0, 0x0, 0x0, 0x0)
        /home/bradfitz/src/golang.org/x/build/cmd/gomote/push.go:293 +0x16e fp=0xc42004d3f0 sp=0xc42004d378
main.push.func3(0xc420120d00, 0x35, 0x7bbc40, 0xc4200d51e0, 0x0, 0x0, 0x0, 0x0)
        /home/bradfitz/src/golang.org/x/build/cmd/gomote/push.go:135 +0x268 fp=0xc42004d490 sp=0xc42004d3f0
path/filepath.walk(0xc420120d00, 0x35, 0x7bbc40, 0xc4200d51e0, 0xc420373360, 0x0, 0x0)
        /home/bradfitz/go/src/path/filepath/path.go:349 +0x71 fp=0xc42004d560 sp=0xc42004d490
path/filepath.walk(0xc4205fcc90, 0x21, 0x7bbc40, 0xc4200d45b0, 0xc420373360, 0x0, 0x0)
        /home/bradfitz/go/src/path/filepath/path.go:374 +0x324 fp=0xc42004d630 sp=0xc42004d560
path/filepath.walk(0xc4202561c0, 0x1c, 0x7bbc40, 0xc420100c30, 0xc420373360, 0x0, 0x0)
        /home/bradfitz/go/src/path/filepath/path.go:374 +0x324 fp=0xc42004d700 sp=0xc42004d630
path/filepath.walk(0xc420372880, 0x15, 0x7bbc40, 0xc42036d450, 0xc420373360, 0x0, 0x0)
        /home/bradfitz/go/src/path/filepath/path.go:374 +0x324 fp=0xc42004d7d0 sp=0xc42004d700
path/filepath.walk(0xc4200120c7, 0x11, 0x7bbc40, 0xc42011a1a0, 0xc420373360, 0x0, 0x1)
        /home/bradfitz/go/src/path/filepath/path.go:374 +0x324 fp=0xc42004d8a0 sp=0xc42004d7d0
path/filepath.Walk(0xc4200120c7, 0x11, 0xc420373360, 0x0, 0xc42037b260)
        /home/bradfitz/go/src/path/filepath/path.go:396 +0xc6 fp=0xc42004d8e8 sp=0xc42004d8a0
main.push(0xc42000c260, 0x1, 0x1, 0x4, 0xc42002dd50)
        /home/bradfitz/src/golang.org/x/build/cmd/gomote/push.go:142 +0x465 fp=0xc42004de48 sp=0xc42004d8e8
main.main()
        /home/bradfitz/src/golang.org/x/build/cmd/gomote/gomote.go:128 +0x151 fp=0xc42004df50 sp=0xc42004de48
runtime.main()
        /home/bradfitz/go/src/runtime/proc.go:189 +0x20a fp=0xc42004dfa0 sp=0xc42004df50
runtime.goexit()
        /home/bradfitz/go/src/runtime/asm_amd64.s:2058 +0x1 fp=0xc42004dfa8 sp=0xc42004dfa0

I will roll this back if the roll-forward fix can't be made soon.

gopherbot pushed a commit that referenced this issue May 10, 2016
@bradfitz
crypto/sha1: disable crashing AVX2 optimizations for now
78ff743 
Updates #15617

Change-Id: I2104776f8e789d987b4f2f7f08f2ebe979b747a1
Reviewed-on: https://go-review.googlesource.com/23001
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Minux Ma <minux@golang.org>
@rsc
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rsc commented May 16, 2016

/cc @TocarIP

@minux minux mentioned this issue May 17, 2016
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CL https://golang.org/cl/23138 mentions this issue.

@golang golang locked and limited conversation to collaborators May 26, 2017
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