dect
/
libpcap
Archived
13
0
Fork 0
Code Releases Activity

From Kris Katterjohn, with some additional changes from Paolo Abeni: fix 

some sscanf() calls:

	The first change involves a sscanf() that has '%n' in the format
	string, which shouldn't be checked for in the return value
	(stored in "ntok").  This is done correctly elsewhere in the code
	(and even commented on) such that the return value is checked for
	everything but the %n modifier.

	And a few lines after this, a sscanf() is done for '%d' and the
	return value is stored in "ret".  However, the same exact line
	from the above mishap is used here, not even checking the right
	variable or number of conversions! It checks "ntok" for 2 when
	it should check "ret" for 1.
This commit is contained in:
guy 2007-11-30 19:53:06 +00:00
parent 8f6e068349
commit baa8f1a126
1 changed files with 11 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
pcap-usb-linux.c
View File

@ -29,11 +29,12 @@
*
* USB sniffing API implementation for Linux platform
* By Paolo Abeni <paolo.abeni@email.it>
* Modifications: Kris Katterjohn <katterjohn@gmail.com>
*
*/
#ifndef lint
static const char rcsid[] _U_ =
"@(#) $Header: /tcpdump/master/libpcap/pcap-usb-linux.c,v 1.16 2007-09-14 01:55:49 guy Exp $ (LBL)";
"@(#) $Header: /tcpdump/master/libpcap/pcap-usb-linux.c,v 1.17 2007-11-30 19:53:06 guy Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
@ -528,8 +529,15 @@ usb_stats_linux(pcap_t *handle, struct pcap_stat *stats)
/* extract info on dropped urbs */
for (consumed=0; consumed < ret; ) {
/* from the sscanf man page:
* The C standard says: "Execution of a %n directive does
* not increment the assignment count returned at the completion
* of execution" but the Corrigendum seems to contradict this.
* Do not make any assumptions on the effect of %n conversions
* on the return value and explicitly check for cnt assignmet*/
cnt = -1;
int ntok = sscanf(ptr, "%s%n", token, &cnt);
if (ntok != 2)
if ((ntok < 1) || (cnt < 0))
break;
consumed += cnt;
ptr += cnt;
@ -537,7 +545,7 @@ usb_stats_linux(pcap_t *handle, struct pcap_stat *stats)
ret = sscanf(ptr, "%d", &stats->ps_drop);
else
ret = sscanf(ptr, "%d", &dummy);
if (ntok != 2)
if (ntok != 1)
break;
consumed += cnt;
ptr += cnt;