[Pcsclite-muscle] Valgrind error in SCardEstablishContext(): socketcall.connect points to uninitialized bytes
Thomas Bajer
thomas.bajer
Wed Jul 19 06:14:17 PDT 2017
Hello,
I would like to report an error message which valgrind throws the first
time "SCardEstablishContext()" is called. The error message does not
appear again when a second call to the function is done.
Please have a look at the attached minimal example code. The program
connects and disconnects to a smartcard two times. In order for the
valgrind message to trigger, a smartcard has to be connected to the PC
and the pcscd service has to be running.
The code was linked with the newest stable release, 1.8.22.
The code is compiled and linked on a FreeBSD system running FreeBSD 10.3
(AMD64), the executable is then copied to a pfsense Box which also runs
FreeBSD 10.3 with the same pcscd version.
It would be great if a developer could look at this and commit a fix for
this message.
Below is the exampleConnect.c example, the build command and the
valgrind error log.
Regards,
Thomas Bajer
Valgrind output:
$ /usr/local/bin/valgrind --leak-check=full /root/example
==63949== Memcheck, a memory error detector
==63949== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==63949== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright
info
==63949== Command: /root/example
==63949==
Establish context
==63949== Syscall param socketcall.connect(serv_addr..sa_len) points to
uninitialised byte(s)
==63949== at 0x535555A: _connect (in /lib/libc.so.7)
==63949== by 0x57EDA65: ??? (in /lib/libthr.so.3)
==63949== by 0x4E309B9: ??? (in /usr/local/lib/libpcsclite.so.1.0.0)
==63949== by 0x4E2C20A: SCardEstablishContext (in
/usr/local/lib/libpcsclite.so.1.0.0)
==63949== by 0x400AC2: connectToSmartcard (in /root/example)
==63949== by 0x400A1B: main (in /root/example)
==63949== Address 0x7ff0009d8 is on thread 1's stack
==63949==
List readers
Connect to card
Smartcard connected!
Disconnect card...
Free reader...
Release context...
Establish context
List readers
Connect to card
Smartcard connected!
Disconnect card...
Free reader...
Release context...
DONE!
==63949==
==63949== HEAP SUMMARY:
==63949== in use at exit: 5,368 bytes in 8 blocks
==63949== total heap usage: 26 allocs, 18 frees, 6,210 bytes allocated
==63949==
==63949== LEAK SUMMARY:
==63949== definitely lost: 0 bytes in 0 blocks
==63949== indirectly lost: 0 bytes in 0 blocks
==63949== possibly lost: 0 bytes in 0 blocks
==63949== still reachable: 5,368 bytes in 8 blocks
==63949== suppressed: 0 bytes in 0 blocks
==63949== Reachable blocks (those to which a pointer was found) are not
shown.
==63949== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==63949==
==63949== For counts of detected and suppressed errors, rerun with: -v
==63949== Use --track-origins=yes to see where uninitialised values come
from
==63949== ERROR SUMMARY: 2 errors from 1 contexts (suppressed: 0 from 0)
Program code:
/*
* exampleConnect.c
*
* Created on: 19.07.2017
* Author: User
*/
/* compile command */
/* gcc -o example exampleConnect.c -I/usr/local/include/PCSC -lpcsclite
-lusb */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
//#include <usb.h>
#include <errno.h>
#include <stdint.h>
#ifdef __APPLE__
#include <PCSC/winscard.h>
#include <PCSC/wintypes.h>
#else
#include <winscard.h>
#endif
int connectToSmartcard( SCARDCONTEXT *hContext,
SCARDHANDLE *hCard,
LPTSTR *mszReaders);
void disconnectSmartcard(SCARDCONTEXT *hContext, SCARDHANDLE *hCard,
LPTSTR *mszReaders);
int main(int argc, char **argv) {
SCARDCONTEXT hContext;
SCARDHANDLE hCard;
LPTSTR mszReaders;
int ret = connectToSmartcard(&hContext, &hCard, &mszReaders);
if(ret == 0)
{
disconnectSmartcard(&hContext, &hCard, &mszReaders);
}
ret = connectToSmartcard(&hContext, &hCard, &mszReaders);
if(ret == 0)
{
disconnectSmartcard(&hContext, &hCard, &mszReaders);
}
printf("DONE!\n");
return ret;
}
int connectToSmartcard( SCARDCONTEXT *hContext,
SCARDHANDLE *hCard,
LPTSTR *mszReaders)
{
LONG rv = 0;
DWORD dwReaders, dwActiveProtocol ;
// Init context
printf("Establish context\n");
rv = SCardEstablishContext(SCARD_SCOPE_SYSTEM, NULL, NULL, hContext);
if (SCARD_S_SUCCESS != rv)
{
return -1;
}
// Get available smartcard readers
#ifdef SCARD_AUTOALLOCATE
dwReaders = SCARD_AUTOALLOCATE;
printf("List readers\n");
rv = SCardListReaders(*hContext, NULL, (LPTSTR)mszReaders, &dwReaders);
if (SCARD_S_SUCCESS != rv)
{
SCardReleaseContext(*hContext);
return -1;
}
#else
printf("List readers\n");
rv = SCardListReaders(*hContext, NULL, NULL, &dwReaders);
if (SCARD_S_SUCCESS != rv)
{
SCardReleaseContext(*hContext);
return -1;
}
printf("Allocate readers\n");
mszReaders = calloc(dwReaders, sizeof(char));
rv = SCardListReaders(*hContext, NULL, *mszReaders, &dwReaders);
if(SCARD_S_SUCCESS != rv)
{
SCardFreeMemory(*hContext, mszReaders);
SCardReleaseContext(*hContext);
return -1;
}
#endif
printf("Connect to card\n");
// Connect to smartcard
rv = SCardConnect( *hContext,
*mszReaders,
SCARD_SHARE_SHARED,
SCARD_PROTOCOL_T0 | SCARD_PROTOCOL_T1,
hCard,
&dwActiveProtocol);
if (SCARD_S_SUCCESS != rv)
{
SCardFreeMemory(*hContext, *mszReaders);
SCardReleaseContext(*hContext);
return -1;
}
printf("Smartcard connected!\n");
return 0;
}
void disconnectSmartcard(SCARDCONTEXT *hContext, SCARDHANDLE *hCard,
LPTSTR *mszReaders)
{
printf("Disconnect card...\n");
SCardDisconnect(*hCard, SCARD_LEAVE_CARD);
printf("Free reader...\n");
#ifdef SCARD_AUTOALLOCATE
SCardFreeMemory(*hContext, *mszReaders);
#else
free(*mszReaders);
#endif
printf("Release context...\n");
SCardReleaseContext(*hContext);
// system("service pcscd onestop");
// printf("Smartcard disconnected!\n");
}
--
Thomas Bajer
Security Engineer
_________________________________
PHYSEC GmbH
Geb?ude ID | Raum 05/409
Universit?tsstra?e 150
44801 Bochum, Germany
Web: http://www.physec.de
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