CVE-2022-49978

MEDIUM EPSS 10.4%

Published Jun 18, 20251y ago · Modified Jun 17, 20262w ago

5.5 CVSS 3.1

Medium

Published Jun 18, 2025 1y ago

Last Modified Jun 17, 2026 2w ago

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 Details

Base Score

5.5

Exploitability

1.8

Impact

3.6

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector Local

Attack Complexity Low

Privileges Required Low

User Interaction None

Scope Unchanged

Confidentiality None

Integrity None

Availability High

Threat Intelligence

EPSS Exploit Probability

10.4% percentile

Exploit & Patch Status

No Known Exploit

Patch Available

Weaknesses 1

CWE-369

Affected Products 9

Vendor	Product	Version	Range
linux	linux_kernel	*	<4.9.327
linux	linux_kernel	*	≥4.10 – <4.14.292
linux	linux_kernel	*	≥4.15 – <4.19.257
linux	linux_kernel	*	≥4.20 – <5.4.212
linux	linux_kernel	*	≥5.5 – <5.10.141
linux	linux_kernel	*	≥5.11 – <5.15.65
linux	linux_kernel	*	≥5.16 – <5.19.7
linux	linux_kernel	6.0	any
linux	linux_kernel	6.0	any

References 8

git.kernel.org https://git.kernel.org/stable/c/0f1174f4972ea9fad6becf8881d71adca8e9ca91

Patch
git.kernel.org https://git.kernel.org/stable/c/19f953e7435644b81332dd632ba1b2d80b1e37af

Patch
git.kernel.org https://git.kernel.org/stable/c/34c3dea1189525cd533071ed5c176fc4ea8d982b

Patch
git.kernel.org https://git.kernel.org/stable/c/3ec326a6a0d4667585ca595f438c7293e5ced7c4

Patch
git.kernel.org https://git.kernel.org/stable/c/7d9591b32a9092fc6391a316b56e8016c6181c3d

Patch
git.kernel.org https://git.kernel.org/stable/c/7f88cdfea8d7f4dbaf423d808241403b2bb945e4

Patch
git.kernel.org https://git.kernel.org/stable/c/8fc778ee2fb2853f7a3531fa7273349640d8e4e9

Patch
git.kernel.org https://git.kernel.org/stable/c/cb4bb011a683532841344ca7f281b5e04389b4f8

Patch

Remediation

git.kernel.org https://git.kernel.org/stable/c/0f1174f4972ea9fad6becf8881d71adca8e9ca91

Patch
git.kernel.org https://git.kernel.org/stable/c/19f953e7435644b81332dd632ba1b2d80b1e37af

Patch
git.kernel.org https://git.kernel.org/stable/c/34c3dea1189525cd533071ed5c176fc4ea8d982b

Patch
git.kernel.org https://git.kernel.org/stable/c/3ec326a6a0d4667585ca595f438c7293e5ced7c4

Patch
git.kernel.org https://git.kernel.org/stable/c/7d9591b32a9092fc6391a316b56e8016c6181c3d

Patch
git.kernel.org https://git.kernel.org/stable/c/7f88cdfea8d7f4dbaf423d808241403b2bb945e4

Patch
git.kernel.org https://git.kernel.org/stable/c/8fc778ee2fb2853f7a3531fa7273349640d8e4e9

Patch
git.kernel.org https://git.kernel.org/stable/c/cb4bb011a683532841344ca7f281b5e04389b4f8

Patch