Browse code
pkg/tarsum: fix panic with dynamic buffer
When read is called on a tarsum with a two different read sizes, specifically the second call larger than the first, the dynamic buffer does not get reallocated causing a slice read error.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
Derek McGowan authored on 2014/09/26 07:58:35Showing 2 changed files
| ... | ... |
@@ -179,7 +179,7 @@ func (ts *tarSum) Read(buf []byte) (int, error) {
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| 179 | 179 |
if ts.finished {
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| 180 | 180 |
return ts.bufWriter.Read(buf) |
| 181 | 181 |
} |
| 182 |
- if ts.bufData == nil {
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+ if len(ts.bufData) < len(buf) {
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| 183 | 183 |
switch {
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| 184 | 184 |
case len(buf) <= buf8K: |
| 185 | 185 |
ts.bufData = make([]byte, buf8K) |
| ... | ... |
@@ -191,7 +191,7 @@ func (ts *tarSum) Read(buf []byte) (int, error) {
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| 191 | 191 |
ts.bufData = make([]byte, len(buf)) |
| 192 | 192 |
} |
| 193 | 193 |
} |
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- buf2 := ts.bufData[:len(buf)-1] |
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+ buf2 := ts.bufData[:len(buf)] |
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| 195 | 195 |
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| 196 | 196 |
n, err := ts.tarR.Read(buf2) |
| 197 | 197 |
if err != nil {
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| ... | ... |
@@ -274,6 +274,22 @@ func TestTarSums(t *testing.T) {
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| 274 | 274 |
t.Errorf("%q :: %q", err, layer.filename)
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| 275 | 275 |
continue |
| 276 | 276 |
} |
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+ |
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+ // Read variable number of bytes to test dynamic buffer |
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+ dBuf := make([]byte, 1) |
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+ _, err = ts.Read(dBuf) |
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+ if err != nil {
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+ t.Errorf("failed to read 1B from %s: %s", layer.filename, err)
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+ continue |
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+ } |
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+ dBuf = make([]byte, 16*1024) |
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+ _, err = ts.Read(dBuf) |
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+ if err != nil {
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+ t.Errorf("failed to read 16KB from %s: %s", layer.filename, err)
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+ continue |
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+ } |
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+ |
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+ // Read and discard remaining bytes |
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| 277 | 293 |
_, err = io.Copy(ioutil.Discard, ts) |
| 278 | 294 |
if err != nil {
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| 279 | 295 |
t.Errorf("failed to copy from %s: %s", layer.filename, err)
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