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Bug 1801834 - Fix iptables-restore --noflush with empty lines in input
Summary: Fix iptables-restore --noflush with empty lines in input
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 8
Classification: Red Hat
Component: iptables
Version: 8.2
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: rc
: 8.2
Assignee: Phil Sutter
QA Contact: Jiri Peska
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2020-02-11 17:28 UTC by Phil Sutter
Modified: 2023-02-12 20:47 UTC (History)
3 users (show)

Fixed In Version: iptables-1.8.4-8.el8
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed: 2020-04-28 17:00:30 UTC
Type: Bug
Target Upstream Version:
Embargoed:
pm-rhel: mirror+

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Netfilter 1400 0 None None None 2020-02-14 15:47:49 UTC
Red Hat Issue Tracker RHELPLAN-37388 0 None None None 2023-02-12 20:47:39 UTC
Red Hat Product Errata RHEA-2020:1889 0 None None None 2020-04-28 17:00:39 UTC

Description Phil Sutter 2020-02-11 17:28:38 UTC 
Same problem as described here:

https://bugzilla.netfilter.org/show_bug.cgi?id=1400

Fix sent upstream: 

https://lore.kernel.org/netfilter-devel/20200211170913.2374-1-phil@nwl.cc/
Comment 1 Phil Sutter 2020-02-12 14:19:23 UTC 
Upstream commit to backport:

commit 8e76391096f12212985c401ee83a67990aa27a29 (HEAD -> upstream, origin-rw/master)
Author: Phil Sutter <phil>
Date:   Tue Feb 11 16:52:59 2020 +0100

    xtables-restore: fix for --noflush and empty lines
    
    Lookahead buffer used for cache requirements estimate in restore
    --noflush separates individual lines with nul-chars. Two consecutive
    nul-chars are interpreted as end of buffer and remaining buffer content
    is skipped.
    
    Sadly, reading an empty line (i.e., one containing a newline character
    only) caused double nul-chars to appear in buffer as well, leading to
    premature stop when reading cached lines from buffer.
    
    To fix that, make use of xtables_restore_parse_line() skipping empty
    lines without calling strtok() and just leave the newline character in
    place. A more intuitive approach, namely skipping empty lines while
    buffering, is deliberately not chosen as that would cause wrong values
    in 'line' variable.
    
    Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1400
    Fixes: 09cb517949e69 ("xtables-restore: Improve performance of --noflush operation")
    Signed-off-by: Phil Sutter <phil>
    Acked-by: Arturo Borrero Gonzalez <arturo>
Comment 8 errata-xmlrpc 2020-04-28 17:00:30 UTC 
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/RHEA-2020:1889
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