CVE-2021-47427: scsi: iscsi: Fix iscsi_task use after free

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-21 · updated 2026-08-04
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: iscsi: Fix iscsi_task use after free Commit d39df158518c ("scsi: iscsi: Have abort handler get ref to conn") added iscsi_get_conn()/iscsi_put_conn() calls during abort handling but then also changed the handling of the case where we detect an already completed task where we now end up doing a goto to the common put/cleanup code. This results in a iscsi_task use after free, because the common cleanup code will do a put on the iscsi_task. This reverts the goto and moves the iscsi_get_conn() to after we've checked if the iscsi_task is valid.

Affected products

Linux kernel: from 5.14 before 5.14.12; 5.15-rc1, 5.15-rc2, 5.15-rc3, 5.15-rc4 — fixed in 5.14.12

How to fix

Upgrade to a fixed version: Linux kernel 5.14.12. Check the vendor advisory for mitigations.

References

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