{"cve":"CVE-2022-49978","nvd":{"published":"2025-06-18T11:15:25.243","modified":"2026-06-17T05:19:39.880","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: fb_pm2fb: Avoid potential divide by zero error\n\nIn `do_fb_ioctl()` of fbmem.c, if cmd is FBIOPUT_VSCREENINFO, var will be\ncopied from user, then go through `fb_set_var()` and\n`info->fbops->fb_check_var()` which could may be `pm2fb_check_var()`.\nAlong the path, `var->pixclock` won't be modified. This function checks\nwhether reciprocal of `var->pixclock` is too high. If `var->pixclock` is\nzero, there will be a divide by zero error. So, it is necessary to check\nwhether denominator is zero to avoid crash. As this bug is found by\nSyzkaller, logs are listed below.\n\ndivide error in pm2fb_check_var\nCall Trace:\n <TASK>\n fb_set_var+0x367/0xeb0 drivers/video/fbdev/core/fbmem.c:1015\n do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1110\n fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1189","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-369"],"references":["https://git.kernel.org/stable/c/0f1174f4972ea9fad6becf8881d71adca8e9ca91","https://git.kernel.org/stable/c/19f953e7435644b81332dd632ba1b2d80b1e37af","https://git.kernel.org/stable/c/34c3dea1189525cd533071ed5c176fc4ea8d982b","https://git.kernel.org/stable/c/3ec326a6a0d4667585ca595f438c7293e5ced7c4","https://git.kernel.org/stable/c/7d9591b32a9092fc6391a316b56e8016c6181c3d"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:03:23.287444849+00:00"},"epss":{"cve":"CVE-2022-49978","score":0.00253,"percentile":0.16891,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}