CVE-2021-47439
Global infos:
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
CVE Status: Awaiting Analysis
References:
Metrics:
| Attribute | Value |
|---|---|
| Attack Complexity | LOW |
| Attack Vector | LOCAL |
| Availability Impact | HIGH |
| Base Score | 5.5 |
| Base Severity | MEDIUM |
| Confidentiality Impact | NONE |
| Integrity Impact | NONE |
| Privileges Required | LOW |
| Scope | UNCHANGED |
| User Interaction | NONE |
| Vector String | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| Exploitability Score | 1.8 |
| Impact Score | 3.6 |
| Source | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| Type | Secondary |