NULL Pointer Dereference Affecting kernel-zfcpdump package, versions <5.14.21-150500.55.68.1


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.05% (19th percentile)

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  • Snyk IDSNYK-SLES155-KERNELZFCPDUMP-7375888
  • published26 Jun 2024
  • disclosed25 Jun 2024

Introduced: 25 Jun 2024

CVE-2021-47439  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

Upgrade SLES:15.5 kernel-zfcpdump to version 5.14.21-150500.55.68.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-zfcpdump package and not the kernel-zfcpdump package as distributed by SLES. See How to fix? for SLES:15.5 relevant fixed versions and status.

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

net: dsa: microchip: Added the condition for scheduling ksz_mib_read_work

When the ksz module is installed and removed using rmmod, kernel crashes with null pointer dereferrence error. During rmmod, ksz_switch_remove function tries to cancel the mib_read_workqueue using cancel_delayed_work_sync routine and unregister switch from dsa.

During dsa_unregister_switch it calls ksz_mac_link_down, which in turn reschedules the workqueue since mib_interval is non-zero. Due to which queue executed after mib_interval and it tries to access dp->slave. But the slave is unregistered in the ksz_switch_remove function. Hence kernel crashes.

To avoid this crash, before canceling the workqueue, resetted the mib_interval to 0.

v1 -> v2: -Removed the if condition in ksz_mib_read_work

CVSS Base Scores

version 3.1