Remove strlen call from Curl_client_write. #6954
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bagder
reviewed
Apr 25, 2021
| @@ -616,8 +616,6 @@ CURLcode Curl_client_write(struct Curl_easy *data, | |||
| size_t len) | |||
| { | |||
| struct connectdata *conn = data->conn; | |||
| if(0 == len) | |||
| len = strlen(ptr); | |||
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how about also adding...
DEBUGASSERT(len);... to better catch mistakes at least in debug-builds.
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Good call on that assert. Looks like the fuzzer caught something on it: |
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I think it highlights a genuine bug where the code passes on a zero but didn't intend a diff --git a/lib/transfer.c b/lib/transfer.c
index 56ad5e612..c31e22e00 100644
--- a/lib/transfer.c
+++ b/lib/transfer.c
@@ -828,21 +828,21 @@ static CURLcode readwrite_data(struct Curl_easy *data,
error here, be sure to check over the almost identical code
in http_chunks.c.
Make sure that ALL_CONTENT_ENCODINGS contains all the
encodings handled here. */
if(data->set.http_ce_skip || !k->writer_stack) {
- if(!k->ignorebody) {
+ if(!k->ignorebody && nread) {
#ifndef CURL_DISABLE_POP3
if(conn->handler->protocol & PROTO_FAMILY_POP3)
result = Curl_pop3_write(data, k->str, nread);
else
#endif /* CURL_DISABLE_POP3 */
result = Curl_client_write(data, CLIENTWRITE_BODY, k->str,
nread);
}
}
- else if(!k->ignorebody)
+ else if(!k->ignorebody && nread)
result = Curl_unencode_write(data, k->writer_stack, k->str, nread);
}
k->badheader = HEADER_NORMAL; /* taken care of now */
if(result) |
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Your proposed fix looks good to me. Thanks for spotting that. I've been trying to get the curl-fuzzer repo running, but hitting errors with |
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Feel free to add that patch as a commit here so that we can see if there seems to be any remaining flaws to fix. |
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Another fuzz failure, this time in |
At all call sites with an explicit 0 len, pass an appropriate nonzero len.
|
Thanks! |
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At all call sites with an explicit 0 len, pass an appropriate nonzero len.
Fixes #6952