47066036a0
If the input hostname is "[", hlen will underflow to max of size_t when
it is subtracted with 2.
hostname[hlen] will then cause a warning by ubsanitizer:
runtime error: addition of unsigned offset to 0x<snip> overflowed to
0x<snip>
I think that in practice, the generated code will work, and the output
of hostname[hlen] will be the first character "[".
This can be demonstrated by the following program (tested in both clang
and gcc, with -O3)
int main() {
char* hostname=strdup("[");
size_t hlen = strlen(hostname);
hlen-=2;
hostname++;
printf("character is %d\n",+hostname[hlen]);
free(hostname-1);
}
I found this through fuzzing, and even if it seems harmless, the proper
thing is to return early with an error.
Closes #4389
|
||
|---|---|---|
| .github | ||
| CMake | ||
| docs | ||
| include | ||
| lib | ||
| m4 | ||
| packages | ||
| plan9 | ||
| projects | ||
| scripts | ||
| src | ||
| tests | ||
| winbuild | ||
| .cirrus.yml | ||
| .dir-locals.el | ||
| .gitattributes | ||
| .gitignore | ||
| .lgtm.yml | ||
| .mailmap | ||
| .travis-iconv-env.sh | ||
| .travis.yml | ||
| acinclude.m4 | ||
| appveyor.yml | ||
| buildconf | ||
| buildconf.bat | ||
| CHANGES | ||
| CMakeLists.txt | ||
| configure.ac | ||
| COPYING | ||
| curl-config.in | ||
| GIT-INFO | ||
| libcurl.pc.in | ||
| MacOSX-Framework | ||
| Makefile.am | ||
| Makefile.dist | ||
| maketgz | ||
| README | ||
| README.md | ||
| RELEASE-NOTES | ||
| SECURITY.md | ||
Curl is a command-line tool for transferring data specified with URL syntax. Find out how to use curl by reading the curl.1 man page or the MANUAL document. Find out how to install Curl by reading the INSTALL document.
libcurl is the library curl is using to do its job. It is readily available to be used by your software. Read the libcurl.3 man page to learn how!
You find answers to the most frequent questions we get in the FAQ document.
Study the COPYING file for distribution terms and similar. If you distribute curl binaries or other binaries that involve libcurl, you might enjoy the LICENSE-MIXING document.
Contact
If you have problems, questions, ideas or suggestions, please contact us by posting to a suitable mailing list.
All contributors to the project are listed in the THANKS document.
Website
Visit the curl web site for the latest news and downloads.
Git
To download the very latest source from the Git server do this:
git clone https://github.com/curl/curl.git
(you'll get a directory named curl created, filled with the source code)
Security problems
Report suspected security problems via our HackerOne page and not in public!
Notice
Curl contains pieces of source code that is Copyright (c) 1998, 1999 Kungliga Tekniska Högskolan. This notice is included here to comply with the distribution terms.
Backers
Thank you to all our backers! 🙏 [Become a backer]
Sponsors
Support this project by becoming a sponsor. Your logo will show up here with a link to your website. [Become a sponsor]
