Note: This bug is displayed in read-only format because
the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Upstream commit to backport:
commit 545edb7a8ef0a8acf991b1b7857fddc24d7b151a
Author: Phil Sutter <phil>
Date: Wed Sep 28 23:26:42 2022 +0200
monitor: Sanitize startup race condition
During startup, 'nft monitor' first fetches the current ruleset and then
keeps this cache up to date based on received events. This is racey, as
any ruleset changes in between the initial fetch and the socket opening
are not recognized.
This script demonstrates the problem:
| #!/bin/bash
|
| while true; do
| nft flush ruleset
| iptables-nft -A FORWARD
| done &
| maniploop=$!
|
| trap "kill $maniploop; kill \$!; wait" EXIT
|
| while true; do
| nft monitor rules >/dev/null &
| sleep 0.2
| kill $!
| done
If the table add event is missed, the rule add event callback fails to
deserialize the rule and calls abort().
Avoid the inconvenient program exit by returning NULL from
netlink_delinearize_rule() instead of aborting and make callers check
the return value.
Signed-off-by: Phil Sutter <phil>
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory (nftables bug fix and enhancement update), and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHBA-2023:0950
Upstream commit to backport: commit 545edb7a8ef0a8acf991b1b7857fddc24d7b151a Author: Phil Sutter <phil> Date: Wed Sep 28 23:26:42 2022 +0200 monitor: Sanitize startup race condition During startup, 'nft monitor' first fetches the current ruleset and then keeps this cache up to date based on received events. This is racey, as any ruleset changes in between the initial fetch and the socket opening are not recognized. This script demonstrates the problem: | #!/bin/bash | | while true; do | nft flush ruleset | iptables-nft -A FORWARD | done & | maniploop=$! | | trap "kill $maniploop; kill \$!; wait" EXIT | | while true; do | nft monitor rules >/dev/null & | sleep 0.2 | kill $! | done If the table add event is missed, the rule add event callback fails to deserialize the rule and calls abort(). Avoid the inconvenient program exit by returning NULL from netlink_delinearize_rule() instead of aborting and make callers check the return value. Signed-off-by: Phil Sutter <phil>