CVE-2021-47356

mISDN: fix possible use-after-free in HFC_cleanup()

HIGH
7.7
CVSS Score
Published: May 21, 2024 at 02:35 PM UTC
Updated: June 17, 2026 at 04:17 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.7
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: mISDN: fix possible use-after-free in HFC_cleanup() This module's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself.

Affected

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

v < 4.4.2762.6.29 ≤ v < 4.14.2402.6.29 ≤ v < 4.19.1982.6.29 ≤ v < 4.4.2762.6.29 ≤ v < 4.9.2762.6.29 ≤ v < 5.10.512.6.29 ≤ v < 5.12.182.6.29 ≤ v < 5.13.32.6.29 ≤ v < 5.142.6.29 ≤ v < 5.4.1334.10 ≤ v < 4.14.2404.15 ≤ v < 4.19.1984.20 ≤ v < 5.4.1334.5 ≤ v < 4.9.2765.11 ≤ v < 5.12.185.13 ≤ v < 5.13.35.5 ≤ v < 5.10.511da177e4c3f42.6.2987c5fa1bb42624254a2013cbbc3b170d6017f5d6
Vendor states this is fixed in 009fc857c5f6 (fixed)
Vendor states this is fixed in 009fc857c5f6fda81f2f7dd851b2d54193a8e733 (fixed)
Vendor states this is fixed in 3ecd228c636e (fixed)
Vendor states this is fixed in 3ecd228c636ee17c14662729737fa07242a93cb0 (fixed)
Vendor states this is fixed in 49331c07ef0f (fixed)
Vendor states this is fixed in 49331c07ef0f8fdfa42b30ba6a83a657b29d7fbe (fixed)
Vendor states this is fixed in 54ff32029289 (fixed)
Vendor states this is fixed in 54ff3202928952a100c477248e65ac6db01258a7 (fixed)
Vendor states this is fixed in 5f2818185da0 (fixed)
Vendor states this is fixed in 5f2818185da0fe82a932f0856633038b66faf124 (fixed)
Vendor states this is fixed in 61370ff07e0a (fixed)
Vendor states this is fixed in 61370ff07e0acc657559a8fac02551dfeb9d3020 (fixed)
Vendor states this is fixed in 7867ddc5f3de (fixed)
Vendor states this is fixed in 7867ddc5f3de7f289aee63233afc0df4b62834c5 (fixed)
Vendor states this is fixed in b7ee9ae1e0cf (fixed)
Vendor states this is fixed in b7ee9ae1e0cf55a037c4a99af2acc5d78cb7802d (fixed)
Vendor states this is fixed in ed7c3739d0a0 (fixed)
Vendor states this is fixed in ed7c3739d0a07e2ec3ccbffe7e93cea01c438cda (fixed)
Vendor states this is fixed in 2.6.29 (unaffected)
Vendor states this is fixed in 4.14.240 (unaffected)
Vendor states this is fixed in 4.19.198 (unaffected)
Vendor states this is fixed in 4.4.276 (unaffected)
Vendor states this is fixed in 4.9.276 (unaffected)
Vendor states this is fixed in 5.10.51 (unaffected)
Vendor states this is fixed in 5.12.18 (unaffected)
Vendor states this is fixed in 5.13.3 (unaffected)
Vendor states this is fixed in 5.14 (unaffected)
Vendor states this is fixed in 5.4.133 (unaffected)

References (9)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/009fc857c5f6fda81f2f7dd851b2d54193a8e733
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/3ecd228c636ee17c14662729737fa07242a93cb0
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/49331c07ef0f8fdfa42b30ba6a83a657b29d7fbe
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/54ff3202928952a100c477248e65ac6db01258a7
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/5f2818185da0fe82a932f0856633038b66faf124
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/61370ff07e0acc657559a8fac02551dfeb9d3020
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/7867ddc5f3de7f289aee63233afc0df4b62834c5
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/b7ee9ae1e0cf55a037c4a99af2acc5d78cb7802d

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

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

CVSS

7.7HIGHCISA-ADP
Attack Vector
LOCAL
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-416

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