CVE-2024-40966

tty: add the option to have a tty reject a new ldisc

MEDIUM
5.5
CVSS Score
Published: July 12, 2024 at 12:32 PM UTC
Updated: June 17, 2026 at 07:46 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: tty: add the option to have a tty reject a new ldisc ... and use it to limit the virtual terminals to just N_TTY. They are kind of special, and in particular, the "con_write()" routine violates the "writes cannot sleep" rule that some ldiscs rely on. This avoids the BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659 when N_GSM has been attached to a virtual console, and gsmld_write() calls con_write() while holding a spinlock, and con_write() then tries to get the console lock.

Affected

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

v < 6.1.962.6.35 ≤ v < 6.1.962.6.35 ≤ v < 6.102.6.35 ≤ v < 6.6.362.6.35 ≤ v < 6.9.76.2 ≤ v < 6.6.366.7 ≤ v < 6.9.72.6.35e1eaea46bb4020b38a141b84f88565d4603f8dd0
Vendor states this is fixed in 287b569a5b914903ba7c438a3c0dbc3410ebb409 (fixed)
Vendor states this is fixed in 3c6332f3bb1578b5b10ac2561247b1d6272ae937 (fixed)
Vendor states this is fixed in 5920ac19964f9e20181f63b410d9200ddbf8dc86 (fixed)
Vendor states this is fixed in 6bd23e0c2bb6c65d4f5754d1456bc9a4427fc59b (fixed)
Vendor states this is fixed in 2.6.35 (unaffected)
Vendor states this is fixed in 6.1.96 (unaffected)
Vendor states this is fixed in 6.10 (unaffected)
Vendor states this is fixed in 6.6.36 (unaffected)
Vendor states this is fixed in 6.9.7 (unaffected)

References (5)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/287b569a5b914903ba7c438a3c0dbc3410ebb409
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/3c6332f3bb1578b5b10ac2561247b1d6272ae937
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/5920ac19964f9e20181f63b410d9200ddbf8dc86
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/6bd23e0c2bb6c65d4f5754d1456bc9a4427fc59b
Source: af854a3a-2127-422b-91ae-364da2661108
https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html

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
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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