{"id":"CVE-2022-49978","summary":"fbdev: fb_pm2fb: Avoid potential divide by zero error","details":"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-\u003efbops-\u003efb_check_var()` which could may be `pm2fb_check_var()`.\nAlong the path, `var-\u003epixclock` won't be modified. This function checks\nwhether reciprocal of `var-\u003epixclock` is too high. If `var-\u003epixclock` 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 \u003cTASK\u003e\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","modified":"2026-04-11T12:44:46.084973Z","published":"2025-06-18T11:00:40.693Z","related":["SUSE-SU-2025:02264-1","SUSE-SU-2025:02308-1","SUSE-SU-2025:02320-1","SUSE-SU-2025:02321-1","SUSE-SU-2025:02322-1","SUSE-SU-2025:02334-1","SUSE-SU-2025:02537-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49978.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0f1174f4972ea9fad6becf8881d71adca8e9ca91"},{"type":"WEB","url":"https://git.kernel.org/stable/c/19f953e7435644b81332dd632ba1b2d80b1e37af"},{"type":"WEB","url":"https://git.kernel.org/stable/c/34c3dea1189525cd533071ed5c176fc4ea8d982b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3ec326a6a0d4667585ca595f438c7293e5ced7c4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7d9591b32a9092fc6391a316b56e8016c6181c3d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7f88cdfea8d7f4dbaf423d808241403b2bb945e4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8fc778ee2fb2853f7a3531fa7273349640d8e4e9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cb4bb011a683532841344ca7f281b5e04389b4f8"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49978.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-49978"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2"},{"fixed":"0f1174f4972ea9fad6becf8881d71adca8e9ca91"},{"fixed":"3ec326a6a0d4667585ca595f438c7293e5ced7c4"},{"fixed":"7f88cdfea8d7f4dbaf423d808241403b2bb945e4"},{"fixed":"7d9591b32a9092fc6391a316b56e8016c6181c3d"},{"fixed":"8fc778ee2fb2853f7a3531fa7273349640d8e4e9"},{"fixed":"34c3dea1189525cd533071ed5c176fc4ea8d982b"},{"fixed":"cb4bb011a683532841344ca7f281b5e04389b4f8"},{"fixed":"19f953e7435644b81332dd632ba1b2d80b1e37af"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2022-49978.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.12"},{"fixed":"4.9.327"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.10.0"},{"fixed":"4.14.292"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.15.0"},{"fixed":"4.19.257"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.20.0"},{"fixed":"5.4.212"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.141"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.65"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"5.19.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2022-49978.json"}}],"schema_version":"1.7.5"}