Check return value of sscanf() #100
Conversation
The variable recvsize is read, but may not have been written. It should be guarded by a check that the call to sscanf returns at least 1.
|
I don't think this is a 'should'. - if 'gets_' returned a value of 0 or less, then break the loop. If not, buf contains something. char buf[64];
if (gets_(client, buf, sizeof(buf)) <= 0)
break;
// parse chunk size
unsigned int recvsize; // this time chunk size
sscanf(buf, "%x", &recvsize);
if (recvsize == 0) {
// end of transfer
completed = true;
} |
|
@szsam Thanks for bringing this up, but as @Hojun-Cho mentioned above, there is no good reason to use CPU clocks for checking the return value of sscanf(). Please let me know if you have other thoughts. |
"buf contains something" does not necessarily mean the sscanf call will succeed. E.g. the buf may contain "GGGGG" -- an invalid hex number. Moreover, recvsize is not initialized. If we do not want to check the return value of sscanf anyway, we should at least initialize recvsize to 0. |
|
Looking at this issue closely again. You are absolutely right. Thanks for the PR. Merged in. |
The variable recvsize is read, but may not have been written. It should be guarded by a check that the call to sscanf returns at least 1.