Bug 1684874
| Summary: | glibc: Add more Linux definitions to <netinet/in.h>, including IP*_PMTUDISC_OMIT | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Daisuke Higashi <daisuke.higashi> |
| Component: | glibc | Assignee: | Florian Weimer <fweimer> |
| Status: | CLOSED ERRATA | QA Contact: | qe-baseos-tools-bugs |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 7.6 | CC: | ashankar, codonell, dj, fweimer, mcermak, mnewsome, pfrankli, skolosov |
| Target Milestone: | rc | Keywords: | Patch |
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | glibc-2.17-284.el7 | Doc Type: | No Doc Update |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2019-08-06 12:49:40 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 1170116 | ||
| Bug Blocks: | 1655768 | ||
Patches backported:
commit 7c70f2272edd4efcc4525f1bbb50e92de1a27a57
Author: Mike Frysinger <vapier>
Date: Thu Jan 30 18:56:56 2014 -0500
linux: bits/in.h: sync with latest kernel headers
This pulls in the latest defines for {g,s}etsockopt.
Reviewed-by: Carlos O'Donell <carlos>
Signed-off-by: Mike Frysinger <vapier>
commit 76e5216e317f39da2bc5bf905721cd9554ee6d09
Author: Joseph Myers <joseph>
Date: Mon Jun 23 15:48:42 2014 +0000
Update headers for Linux 3.15.
This patch updates glibc headers for changes / new definitions in
Linux 3.15. In the course of my review I noticed that
IPV6_PMTUDISC_INTERFACE was absent from glibc despite the inclusion of
IP_PMTUDISC_INTERFACE; I added it along with IP_PMTUDISC_OMIT and
IPV6_PMTUDISC_OMIT. I did not add FALLOC_FL_NO_HIDE_STALE given the
kernel header comment that it is reserved.
I confirmed that this issue is fixed in RHEL7.7 beta. IP_PMTUDISC_OMIT feature of several DNS servers [1] is enabled at compile time and it ignores forged ICMPv4 type3-code4 on IPv4/UDP as expected. Thank you! [1] I have tested NSD 4.1.27 and BIND 9.11.6. Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2019:2118 |
-- Description of problem: The Linux kernel 3.15 introduced a new socket option IP_PMTUDISC_OMIT / IPV6_PMTUDISC_OMIT [1] and the kernel feature itself was backported to RHEL7 kernel [3.10.0-217.el7], but the corresponding macros was not backported to <netinet/in.h>. (actually these macros are defined in /usr/include/bits/in.h --- <netinet/in.h> includes it.) The IP*_PMTUDISC_OMIT sockopt is used to mitigate DNS IP fragment attack [2] by some DNS server implementation by default (if available) [3][4]. Due to missing IP*_PMTUDISC_OMIT macro, this mitigation is not enabled at compile time. Backporting these macros into glibc headers will resolve this issue. -- Version-Release number of selected component (if applicable): I have confirmed this issue on RHEL 7.6. kernel/glibc-related versions: kernel-headers-3.10.0-957.5.1.el7.x86_64 kernel-3.10.0-957.5.1.el7.x86_64 glibc-2.17-260.el7_6.3.x86_64 glibc-common-2.17-260.el7_6.3.x86_64 glibc-headers-2.17-260.el7_6.3.x86_64 glibc-devel-2.17-260.el7_6.3.x86_64 -- How reproducible: 100% -- Steps to Reproduce: Compile and run this code and see if "IP*_PMTUDISC_OMIT defined" or not. ------ #include <netinet/in.h> #include <stdio.h> main() { // IP_PMTUDISC_DONT is available on RHEL7 #if defined (IP_PMTUDISC_DONT) printf("IP_PMTUDISC_DONT defined\n"); #endif #if defined (IPV6_PMTUDISC_DONT) printf("IPV6_PMTUDISC_DONT defined\n"); #endif // IP_PMTUDISC_OMIT is missing on RHEL7 #if defined (IP_PMTUDISC_OMIT) printf("IP_PMTUDISC_OMIT defined\n"); #endif #if defined (IPV6_PMTUDISC_OMIT) printf("IPV6_PMTUDISC_OMIT defined\n"); #endif } ------ -- Actual results: IP*_PMTUDISC_OMIT macro is not defined even if <netinet/in.h> is included. -- Expected results: IP*_PMTUDISC_OMIT macro is defined when <netinet/in.h> is included (and corresponding feature is enabled at DNS server's compile time) -- Additional info: [1] Linux kernel introduced IP*_PMTUDISC_OMIT https://lists.openwall.net/netdev/2014/02/26/4 [2] IP fragmentation attack on DNS https://ripe67.ripe.net/presentations/240-ipfragattack.pdf [3] Unbound 1.5.0 introduced this feature. https://github.com/NLnetLabs/unbound/commit/470b7bda8763c36a7db255d1d981f3ae06d41ba0 [4] BIND 9.9.10 introduced this feature. https://www.isc.org/blogs/bind-april-2017/