https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=7861
Summary: In Wireshark 1.8.x, code fails to check/test return
value from select()
Product: Wireshark
Version: 1.8.2
Platform: All
OS/Version: All
Status: NEW
Severity: Major
Priority: Low
Component: Common utilities (libwsutil)
AssignedTo: bugzilla-admin@xxxxxxxxxxxxx
ReportedBy: wp02855@xxxxxxxxx
Created attachment 9350
--> https://bugs.wireshark.org/bugzilla/attachment.cgi?id=9350
Contains patch (diff -u) for addr_resolv.c in Wireshark 1.8.2
Build Information:
Build information below:
wireshark 1.8.2 (SVN Rev Unknown from unknown)
Copyright 1998-2012 Gerald Combs <gerald@xxxxxxxxxxxxx> and contributors.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Compiled (64-bit) with GTK+ 2.22.1, with Cairo 1.10.2, with Pango 1.28.3, with
GLib 2.28.0, with libpcap, with libz 1.2.5, without POSIX capabilities, without
SMI, without c-ares, without ADNS, without Lua, without Python, with GnuTLS
2.8.6, with Gcrypt 1.4.6, with MIT Kerberos, without GeoIP, without PortAudio,
with AirPcap.
Running on Linux 2.6.37.6-0.7-desktop, with locale POSIX, with libpcap version
1.1.1, with libz 1.2.5, GnuTLS 2.8.6, Gcrypt 1.4.6, without AirPcap.
Built using gcc 4.5.1 20101208 [gcc-4_5-branch revision 167585].
--
In reviewing calls to select() in directory 'epan', file 'addr_resolv.c',
I found that in 3 cases, while select() is called, the return value is
not checked afterwards (in the case of failure, select() will return -1),
the patch below add the proper check for the return value from select(),
and prints a warning message to stderr via fprintf:
--- addr_resolv.c.orig 2012-10-13 13:50:29.020658440 -0700
+++ addr_resolv.c 2012-10-13 13:57:43.117532512 -0700
@@ -2510,7 +2510,10 @@
FD_ZERO(&wfds);
nfds = ares_fds(ghba_chan, &rfds, &wfds);
if (nfds > 0) {
- select(nfds, &rfds, &wfds, NULL, &tv);
+ if (select(nfds, &rfds, &wfds, NULL, &tv) == -1) { /* call to select()
failed */
+ fprintf(stderr, "Warning: call to select() failed, error is %s\n",
strerror(errno));
+ return nro;
+ }
ares_process(ghba_chan, &rfds, &wfds);
}
@@ -3197,7 +3200,10 @@
nfds = ares_fds(ghbn_chan, &rfds, &wfds);
if (nfds > 0) {
tvp = ares_timeout(ghbn_chan, &tv, &tv);
- select(nfds, &rfds, &wfds, NULL, tvp);
+ if (select(nfds, &rfds, &wfds, NULL, tvp) == -1) { /* call to select()
failed */
+ fprintf(stderr, "Warning: call to select() failed, error is %s\n",
strerror(errno));
+ return FALSE;
+ }
ares_process(ghbn_chan, &rfds, &wfds);
}
ares_cancel(ghbn_chan);
@@ -3273,7 +3279,10 @@
nfds = ares_fds(ghbn_chan, &rfds, &wfds);
if (nfds > 0) {
tvp = ares_timeout(ghbn_chan, &tv, &tv);
- select(nfds, &rfds, &wfds, NULL, tvp);
+ if (select(nfds, &rfds, &wfds, NULL, tvp) == -1) { /* call to select()
failed */
+ fprintf(stderr, "Warning: call to select() failed, error is %s\n",
strerror(errno));
+ return FALSE;
+ }
ares_process(ghbn_chan, &rfds, &wfds);
}
ares_cancel(ghbn_chan);
/* call to select() failed */
fprintf(stderr, "Warning: call to select() failed, error is %s\n",
strerror(errno));
return nro;
}
In file 'capture_sync.c', a call to read() does not check
for a return value of -1 (which indicates failure), this
patch tests for this, and adds a warning message to
the code:
--- capture_sync.c.orig 2012-10-13 14:41:09.524965920 -0700
+++ capture_sync.c 2012-10-13 14:42:22.555683640 -0700
@@ -1523,6 +1523,10 @@
/* we have a problem here, try to read some more bytes from the pipe
to debug where the problem really is */
memcpy(msg, header, sizeof(header));
newly = read(pipe_fd, &msg[sizeof(header)], len-sizeof(header));
+ if (newly < 0) { /* error */
+ g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_DEBUG,
+ "read from pipe %d: error(%u): %s", pipe_fd, errno,
g_strerror(errno));
+ }
*err_msg = g_strdup_printf("Unknown message from dumpcap, try to show
it as a string: %s",
msg);
return -1;
A 'make' of wireshark-1.8.2 produces a clean compile.
Bill Parker
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