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| author | Emmanuel T Odeke <emmanuel@orijtech.com> | 2021-03-06 23:14:21 -0800 |
|---|---|---|
| committer | Emmanuel Odeke <emmanuel@orijtech.com> | 2021-03-08 18:49:14 +0000 |
| commit | aafad20b617ee63d58fcd4f6e0d98fe27760678c (patch) | |
| tree | 6359968324c31731f8bcf2376759ba48211b3307 /src/encoding/binary/varint.go | |
| parent | 125eca0f7210da1bbf1a4a1460a87d1c33366b99 (diff) | |
| download | go-aafad20b617ee63d58fcd4f6e0d98fe27760678c.tar.xz | |
encoding/binary: limit bytes read by Uvarint to <= 10
Limits the number of bytes that can be consumed by Uvarint
to MaxVarintLen64 (10) to avoid wasted computations.
With this change, if Uvarint reads more than MaxVarintLen64
bytes, it'll return the erroring byte count of n=-(MaxVarintLen64+1)
which is -11, as per the function signature.
Updated some tests to reflect the new change in expectations of n
when the number of bytes to be read exceeds the limits..
Fixes #41185
Change-Id: Ie346457b1ddb0214b60c72e81128e24d604d083d
Reviewed-on: https://go-review.googlesource.com/c/go/+/299531
Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
Diffstat (limited to 'src/encoding/binary/varint.go')
| -rw-r--r-- | src/encoding/binary/varint.go | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/src/encoding/binary/varint.go b/src/encoding/binary/varint.go index 1fa325dec7..8fe20b5c45 100644 --- a/src/encoding/binary/varint.go +++ b/src/encoding/binary/varint.go @@ -61,8 +61,13 @@ func Uvarint(buf []byte) (uint64, int) { var x uint64 var s uint for i, b := range buf { + if i == MaxVarintLen64 { + // Catch byte reads past MaxVarintLen64. + // See issue https://golang.org/issues/41185 + return 0, -(i + 1) // overflow + } if b < 0x80 { - if i >= MaxVarintLen64 || i == MaxVarintLen64-1 && b > 1 { + if i == MaxVarintLen64-1 && b > 1 { return 0, -(i + 1) // overflow } return x | uint64(b)<<s, i + 1 |