Race Condition Affecting kernel package, versions *


Severity

Recommended
0.0
medium
0
10

Based on CentOS security rating.

Threat Intelligence

EPSS
0.04% (15th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications

Snyk Learn

Learn about Race Condition vulnerabilities in an interactive lesson.

Start learning
  • Snyk IDSNYK-CENTOS7-KERNEL-6522516
  • published3 Apr 2024
  • disclosed2 Apr 2024

Introduced: 2 Apr 2024

CVE-2024-26671  (opens in a new tab)
CWE-362  (opens in a new tab)

How to fix?

There is no fixed version for Centos:7 kernel.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel package and not the kernel package as distributed by Centos. See How to fix? for Centos:7 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

blk-mq: fix IO hang from sbitmap wakeup race

In blk_mq_mark_tag_wait(), __add_wait_queue() may be re-ordered with the following blk_mq_get_driver_tag() in case of getting driver tag failure.

Then in __sbitmap_queue_wake_up(), waitqueue_active() may not observe the added waiter in blk_mq_mark_tag_wait() and wake up nothing, meantime blk_mq_mark_tag_wait() can't get driver tag successfully.

This issue can be reproduced by running the following test in loop, and fio hang can be observed in < 30min when running it on my test VM in laptop.

modprobe -r scsi_debug
modprobe scsi_debug delay=0 dev_size_mb=4096 max_queue=1 host_max_queue=1 submit_queues=4
dev=`ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter*/host*/target*/*/block/* | head -1 | xargs basename`
fio --filename=/dev/&#34;$dev&#34; --direct=1 --rw=randrw --bs=4k --iodepth=1 \
           --runtime=100 --numjobs=40 --time_based --name=test \
        --ioengine=libaio

Fix the issue by adding one explicit barrier in blk_mq_mark_tag_wait(), which is just fine in case of running out of tag.

CVSS Scores

version 3.1