CVE-2021-47364: comedi: Fix memory leak in compat_insnlist()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-21 · updated 2026-06-17
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: comedi: Fix memory leak in compat_insnlist() `compat_insnlist()` handles the 32-bit version of the `COMEDI_INSNLIST` ioctl (whenwhen `CONFIG_COMPAT` is enabled). It allocates memory to temporarily hold an array of `struct comedi_insn` converted from the 32-bit version in user space. This memory is only being freed if there is a fault while filling the array, otherwise it is leaked. Add a call to `kfree()` to fix the leak.

Affected products

Linux kernel: from 5.8 before 5.10.70; from 5.11 before 5.14.9; 5.15-rc1, 5.15-rc2 — fixed in 5.10.70, 5.14.9

How to fix

Upgrade to a fixed version: Linux kernel 5.10.70, 5.14.9. Check the vendor advisory for mitigations.

References

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