5.5

CVE-2022-49940: tty: n_gsm: add sanity check for gsm->receive in gsm_receive_buf()

Analyzed
AliasesUBUNTU-CVE-2022-49940DEBIAN-CVE-2022-49940
Published 18-06-2025Last modified 23-05-2026

Vulnerability summary

CVE-2022-49940 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 14% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.23%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 7 · Related 4
RHSA-2024:2394RHSA-2024:2621RHSA-2024:3138SUSE-SU-2025:02264-1SUSE-SU-2025:02321-1SUSE-SU-2025:02322-1

Timeline

  1. 18-06-2025
    PublishedVulnerability first disclosed.
  2. 23-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: tty: n_gsm: add sanity check for gsm->receive in gsm_receive_buf() A null pointer dereference can happen when attempting to access the "gsm->receive()" function in gsmld_receive_buf(). Currently, the code assumes that gsm->recieve is only called after MUX activation. Since the gsmld_receive_buf() function can be accessed without the need to initialize the MUX, the gsm->receive() function will not be set and a NULL pointer dereference will occur. Fix this by avoiding the call to "gsm->receive()" in case the function is not initialized by adding a sanity check. Call Trace: <TASK> gsmld_receive_buf+0x1c2/0x2f0 drivers/tty/n_gsm.c:2861 tiocsti drivers/tty/tty_io.c:2293 [inline] tty_ioctl+0xa75/0x15d0 drivers/tty/tty_io.c:2692 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.23%

Chance of exploitation in the next 30 days

Percentile

14%

Versus all other CVEs

30-day change

Increase +0.01 pp

From 0.23% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu170 products
  • linuxAll versions (No fix recorded)
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ b8faa754b523a845facdc83120b2ecd290d7fa6d, < 5a82cf64f8ad63caf6bf115642ce44ddbc64311e | ≥ dfa9b6d34aac2154b5e926d7a7a061123bf137c6, < 309aea4b6b813f6678c3a547cfd7fe3a76ffa976 | ≥ 5e59c010c6862da329db17acca086afd8bea1aa8, < 5aa37f9510345a812c0998bcbbc4d88d1dcc4d8b | ≥ 01aecd917114577c423f07cec0d186ad007d76fc, < f16c6d2e58a4c2b972efcf9eb12390ee0ba3befb | 2dc1be365a70699f7dda92fd9e48b84546086070 | ≥ 5.18.18, < 5.19 | ≥ 5.15.61, < 5.15.66 | ≥ 5.19.2, < 5.19.8
  • linux_kernel≥ 5.15.61, < 5.15.66 | ≥ 5.18.18, < 5.19 | ≥ 5.19.2, < 5.19.8 | 6.0:rc1 | 6.0:rc2 | 6.0:rc3
Debian1 product
  • linux< 5.19.11-1

3 vendors · 173 products

References

8 links