When querying a .onion domain, it returns directly without setting bufp to NULL. A subsequent free() that occurs can cause a segmentation fault.
Fix By: Khaidi Chu (@XadillaX)
Quoting RFC 7686:
Name Resolution APIs and Libraries (...) MUST either respond
to requests for .onion names by resolving them according to
[tor-rendezvous] or by responding with NXDOMAIN.
A legacy client may inadvertently attempt to resolve a .onion
name through the DNS. This causes a disclosure that the client
is attempting to use Tor to reach a specific service. Malicious
resolvers could be engineered to capture and record such leaks,
which might have very adverse consequences for the well-being
of the user.
Bug: #196
Fix By: Ben Noordhuis @bnoordhuis
These changes fix a few warnings emitted by recent versions of MSVC when compiling with -W4. Half of the changes are in Windows-specific code, and the other half should be safe no matter the compiler or OS.
The allocation function change is probably the only one that needs explanation. MSVC gives warnings about the function pointers not being stable across DLL boundaries or something to that effect, so for Windows, I've made them be called indirectly, which at least made the compiler happy. I can't say I've tested every linking combination on Windows with them before or after the change, but it seems harmless.
Fix By: Brad Spencer @b-spencer
PR: https://github.com/c-ares/c-ares/pull/192
Add a new ares_library_init_mem() initialization function for the
library which allows the library user to specify their own malloc,
realloc & free equivalents for use library-wide.
Store these function pointers in library-wide global variables,
defaulting to libc's malloc(), realloc() and free().
Change all calls to malloc, realloc and free to use the function pointer
instead. Also ensure that ares_strdup() is always available
(even if the local environment includes strdup(3)), and change the
library code to always use it.
Convert calls to calloc() to use ares_malloc() + memset
check for ssize_t to make it possible to use that when receiving the send()
error code. This is necessary to prevent compiler warnings on some systems.
- Made configure create config.h, and all source files now include setup.h that
might include the proper config.h (or a handicrafted alternative).
- Switched to 'ares_socket_t' type for sockets in ares, since Windows don't
use 'int' for that.
- automake-ified and libool-ified c-ares. Now it builds libcares as a shared
lib on most platforms if wanted. (This bloated the size of the release
archive with another 200K!)
- Makefile.am now uses Makefile.inc for the c sources, h headers and man
pages, to make it easier for other makefiles to use the exact same set of
files.
- Adjusted 'maketgz' to use the new automake magic when building distribution
archives.
Khaidi Chu
Ben Noordhuis
Brad Spencer
David Drysdale
Daniel Stenberg
Yang Tse
hpopescu@ixiacom.com
Dan Fandrich
Steinar H. Gunderson
Gisle Vanem