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
No CVSS.
References
Configurations
No configuration.
History
18 Jun 2025, 11:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-06-18 11:15
Updated : 2025-06-18 13:46
NVD link : CVE-2022-49978
Mitre link : CVE-2022-49978
CVE.ORG link : CVE-2022-49978
JSON object : View
Products Affected
No product.
CWE
No CWE.