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Bug 1752880 - katello-host-tools-tracer stats paths abusively, leading to a hang or slowness of yum command
Summary: katello-host-tools-tracer stats paths abusively, leading to a hang or slownes...
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Satellite
Classification: Red Hat
Component: katello-tracer
Version: 6.5.0
Hardware: All
OS: Linux
high
medium
Target Milestone: 6.8.0
Assignee: Jonathon Turel
QA Contact: Ondrej Gajdusek
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2019-09-17 13:24 UTC by Renaud Métrich
Modified: 2023-12-15 16:46 UTC (History)
8 users (show)

Fixed In Version: tracer-0.7.2-1
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed: 2020-10-27 12:59:02 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Foreman Issue Tracker 29436 0 High Closed katello-host-tools-tracer stats paths abusively, leading to a hang or slowness of yum command 2020-11-03 10:39:05 UTC
Red Hat Product Errata RHSA-2020:4366 0 None None None 2020-10-27 12:59:21 UTC

Description Renaud Métrich 2019-09-17 13:24:33 UTC 
Description of problem:

When having the katello-host-tools-tracer package installed on the system, many processes are scanned when a yum operation is performed.
In particular it seems that arguments of these processes are collected, then stat() is issued on the arguments, which is usually non-sense:

-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------
15160 15:09:27.340215 stat("--no-daemon", 0x7ffec78c75f0) = -1 ENOENT (No such file or directory) <0.000012>
15160 15:09:27.376073 stat("--keep-baud", 0x7ffec78c75f0) = -1 ENOENT (No such file or directory) <0.000012>
15160 15:09:27.380001 stat("--noclear", 0x7ffec78c75f0) = -1 ENOENT (No such file or directory) <0.000013>
...
-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------

If for some reason a process argument looks like a path name on a remote location which is not accessible (e.g. an automount), this makes the yum process hang indefinitely.


Version-Release number of selected component (if applicable):

katello-host-tools-tracer-3.5.0-2.el7sat.noarch
katello-host-tools-tracer-3.3.5-5.el7sat.noarch


How reproducible:

Always (the "dumb" stats calls at least)


Steps to Reproduce:
1. Execute the following python code

# strace -fttTvyy -o /tmp/tracer.strace -s 4096 -e stat -- python << EOF
import katello.tracer
print katello.tracer.query_affected_apps()
EOF

2. Check the strace for "ENOENT"

# grep -w ENOENT /tmp/tracer.strace | grep -v "/"


Actual results:

-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------
...
15160 15:09:27.206950 stat("--system", 0x7ffec78c75f0) = -1 ENOENT (No such file or directory) <0.000011>
15160 15:09:27.206999 stat("--address=systemd:", 0x7ffec78c75f0) = -1 ENOENT (No such file or directory) <0.000010>
15160 15:09:27.207050 stat("--nofork", 0x7ffec78c75f0) = -1 ENOENT (No such file or directory) <0.000010>
15160 15:09:27.207092 stat("--nopidfile", 0x7ffec78c75f0) = -1 ENOENT (No such file or directory) <0.000012>
15160 15:09:27.207136 stat("--systemd-activation", 0x7ffec78c75f0) = -1 ENOENT (No such file or directory) <0.000019>
...
-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------


Expected results:

No stat() done on process arguments, in particular if these are known remote paths


Additional info:

I don't know exactly when these stat calls are performed. It looks like this is done when updating some packages.
Comment 7 Bryan Kearney 2019-11-11 21:23:30 UTC 
This work has not been slated for a release yet.
Comment 8 Jonathon Turel 2020-03-30 13:09:04 UTC 
Created redmine issue https://projects.theforeman.org/issues/29436 from this bug
Comment 9 Bryan Kearney 2020-04-07 14:01:30 UTC 
Moving this bug to POST for triage into Satellite 6 since the upstream issue https://projects.theforeman.org/issues/29436 has been resolved.
Comment 10 Ondrej Gajdusek 2020-08-06 18:33:54 UTC 
Verified using the following versions:
python2-tracer-0.7.3-1
tracer-common-0.7.3-1
katello-host-tools-tracer-3.5.4-1


Reproducer used: https://github.com/FrostyX/tracer/pull/135#issue-395646444

Using the older versions of tracer and katello-host-tools-tracer, tracer is hanging.
katello-host-tools-tracer-3.5.1-2
python2-tracer.noarch-0.7.1-2
tracer-common.noarch-0.7.1-2

-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------
63198 14:01:33.781417 stat("sleeper.py", {st_dev=makedev(253, 0), st_ino=201469471, st_mode=S_IFREG|0644, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=8, st_size=48, st_atime=1596728843 /* 2020-08-06T11:47:23.237744393-0400 */, st_atime_nsec=237744393, st_mtime=1596728833 /* 2020-08-06T11:47:13.313567153-0400 */, st_mtime_nsec=313567153, st_ctime=1596728833 /* 2020-08-06T11:47:13.313567153-0400 */, st_ctime_nsec=313567153}) = 0 <0.000039>
63198 14:01:33.781626 stat("--file", 0x7ffd56997a10) = -1 ENOENT (No such file or directory) <0.000026>
63198 14:01:33.781740 stat("/nfsshare/foo",
Killed


Using the newer versions mentioned above, tracer kills the stat() after a timeout.

-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------
96246 14:07:45.263776 stat("/usr/lib64/libsystemd.so.0.6.0;5f2bd967 (deleted)", 0x7ffdea8cf4d0) = -1 ENOENT (No such file or directory) <0.000031>
96246 14:07:45.263911 stat("/usr/lib64/libsystemd.so.0.6.0;5f2bd967 (deleted)", 0x7ffdea8cf4d0) = -1 ENOENT (No such file or directory) <0.000015>
96265 14:07:45.297730 stat("/nfsshare/foo",  <unfinished ...>) = ?
96265 14:07:45.798067 +++ killed by SIGKILL +++
96266 14:07:45.798133 +++ exited with 0 +++
96246 14:07:45.798150 --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_KILLED, si_pid=96265, si_uid=0, si_status=SIGKILL, si_utime=0, si_stime=0} ---
96246 14:07:45.809671 stat("/usr/lib64/libsystemd.so.0.6.0;5f2bd967 (deleted)", 0x7ffdea8cf4d0) = -1 ENOENT (No such file or directory) <0.000054>
-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------
Comment 13 errata-xmlrpc 2020-10-27 12:59:02 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 (Important: Satellite 6.8 release), 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-2020:4366
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