CVE-2021-46966

ACPI: custom_method: fix potential use-after-free issue

HIGH
7.8
CVSS Score
Published: February 27, 2024 at 06:47 PM UTC
Updated: June 17, 2026 at 04:16 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.8
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: ACPI: custom_method: fix potential use-after-free issue In cm_write(), buf is always freed when reaching the end of the function. If the requested count is less than table.length, the allocated buffer will be freed but subsequent calls to cm_write() will still try to access it. Remove the unconditional kfree(buf) at the end of the function and set the buf to NULL in the -EINVAL error path to match the rest of function.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≥ 5.2.19v ≥ 5.3.44.14.147 ≤ v < 4.14.2334.19.77 ≤ v < 4.19.1914.4.195 ≤ v < 4.4.2694.9.195 ≤ v < 4.9.2695.11 ≤ v < 5.11.205.12 ≤ v < 5.12.35.2.19 ≤ v < 5.35.3.4 ≤ v < 5.45.4 ≤ v < 5.10.365.4 ≤ v < 5.11.205.4 ≤ v < 5.12.35.4 ≤ v < 5.135.4 ≤ v < 5.4.1185.5 ≤ v < 5.10.3635b88a10535edcf62d3e6b7893a8cd506ff98a243d1571d9513369c17e6848476763ebbd10ec2cb4.14.1474.19.774.4.1954.9.1954bda2b79a9d04c8ba31681c66e95877dbb4334165.2.195.3.45.45c12dadcbef8cd55ef1f5dac799bfcbb7ea7db1d6cd4a6eb596a888239fb8ceb6ea15677cab39670424999fbf1f160ade111cb9baab51776e0f9c2e4467fb6ef547aa352dc03397f9474ec84eced5b
Vendor states this is fixed in 1d53ca5d131074c925ce38361fb0376d3bf7e394 (fixed)
Vendor states this is fixed in 62dc2440ebb552aa0d7f635e1697e077d9d21203 (fixed)
Vendor states this is fixed in 72814a94c38a33239793f7622cec6ace1e540c4b (fixed)
Vendor states this is fixed in 8b04d57f30caf76649d0567551589af9a66ca9be (fixed)
Vendor states this is fixed in 90575d1d9311b753cf1718f4ce9061ddda7dfd23 (fixed)
Vendor states this is fixed in a5b26a2e362f572d87e9fd35435680e557052a17 (fixed)
Vendor states this is fixed in b7a5baaae212a686ceb812c32fceed79c03c0234 (fixed)
Vendor states this is fixed in e483bb9a991bdae29a0caa4b3a6d002c968f94aa (fixed)
Vendor states this is fixed in f16737caf41fc06cfe6e49048becb09657074d4b (fixed)
Vendor states this is fixed in 4.14.233 (unaffected)
Vendor states this is fixed in 4.19.191 (unaffected)
Vendor states this is fixed in 4.4.269 (unaffected)
Vendor states this is fixed in 4.9.269 (unaffected)
Vendor states this is fixed in 5.10.36 (unaffected)
Vendor states this is fixed in 5.11.20 (unaffected)
Vendor states this is fixed in 5.12.3 (unaffected)
Vendor states this is fixed in 5.13 (unaffected)
Affected range stops below 5.3, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 5.4 (unaffected)
Vendor states this is fixed in 5.4.118 (unaffected)

References (9)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/1d53ca5d131074c925ce38361fb0376d3bf7e394
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/62dc2440ebb552aa0d7f635e1697e077d9d21203
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/72814a94c38a33239793f7622cec6ace1e540c4b
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/8b04d57f30caf76649d0567551589af9a66ca9be
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/90575d1d9311b753cf1718f4ce9061ddda7dfd23
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/a5b26a2e362f572d87e9fd35435680e557052a17
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/b7a5baaae212a686ceb812c32fceed79c03c0234
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/e483bb9a991bdae29a0caa4b3a6d002c968f94aa

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-416

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