5.5

CVE-2022-49978: fbdev: fb_pm2fb: Avoid potential divide by zero error

Analyzed
AliasesUBUNTU-CVE-2022-49978DEBIAN-CVE-2022-49978
Published 18-06-2025Last modified 11-05-2026

Vulnerability summary

CVE-2022-49978 is a medium (CVSS 5.5) Divide By Zero vulnerability in linux. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 16.9% 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
0.25%
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 7
SUSE-SU-2025:02264-1SUSE-SU-2025:02308-1SUSE-SU-2025:02320-1SUSE-SU-2025:02321-1SUSE-SU-2025:02322-1SUSE-SU-2025:02334-1

Timeline

  1. 18-06-2025
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: fbdev: fb_pm2fb: Avoid potential divide by zero error In `do_fb_ioctl()` of fbmem.c, if cmd is FBIOPUT_VSCREENINFO, var will be copied from user, then go through `fb_set_var()` and `info->fbops->fb_check_var()` which could may be `pm2fb_check_var()`. Along the path, `var->pixclock` won't be modified. This function checks whether reciprocal of `var->pixclock` is too high. If `var->pixclock` is zero, there will be a divide by zero error. So, it is necessary to check whether denominator is zero to avoid crash. As this bug is found by Syzkaller, logs are listed below. divide error in pm2fb_check_var Call Trace: <TASK> fb_set_var+0x367/0xeb0 drivers/video/fbdev/core/fbmem.c:1015 do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1110 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1189

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.25%

Chance of exploitation in the next 30 days

Percentile

17%

Versus all other CVEs

30-day change

Increase +0.01 pp

From 0.25% 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.

Ubuntu112 products
  • linuxAll versions (No fix recorded) | < 4.15.0-201.212 | < 5.4.0-132.148 | < 5.15.0-57.63
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 4.15.0-1147.159 | < 5.4.0-1089.97 | < 5.15.0-1027.31
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 0f1174f4972ea9fad6becf8881d71adca8e9ca91 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 3ec326a6a0d4667585ca595f438c7293e5ced7c4 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 7f88cdfea8d7f4dbaf423d808241403b2bb945e4 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 7d9591b32a9092fc6391a316b56e8016c6181c3d | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 8fc778ee2fb2853f7a3531fa7273349640d8e4e9 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 34c3dea1189525cd533071ed5c176fc4ea8d982b | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < cb4bb011a683532841344ca7f281b5e04389b4f8 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 19f953e7435644b81332dd632ba1b2d80b1e37af | 2.6.12
  • linux_kernel< 4.9.327 | ≥ 4.10, < 4.14.292 | ≥ 4.15, < 4.19.257 | ≥ 4.20, < 5.4.212 | ≥ 5.5, < 5.10.141 | ≥ 5.11, < 5.15.65 | ≥ 5.16, < 5.19.7 | 6.0:rc1 | 6.0:rc2
Debian1 product
  • linux< 6.0.2-1

3 vendors · 115 products

References

11 links
Show all 11 references