{"cve":"CVE-2023-53222","nvd":{"published":"2025-09-15T15:15:48.983","modified":"2026-08-04T10:18:58.560","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\njfs: jfs_dmap: Validate db_l2nbperpage while mounting\n\nIn jfs_dmap.c at line 381, BLKTODMAP is used to get a logical block\nnumber inside dbFree(). db_l2nbperpage, which is the log2 number of\nblocks per page, is passed as an argument to BLKTODMAP which uses it\nfor shifting.\n\nSyzbot reported a shift out-of-bounds crash because db_l2nbperpage is\ntoo big. This happens because the large value is set without any\nvalidation in dbMount() at line 181.\n\nThus, make sure that db_l2nbperpage is correct while mounting.\n\nMax number of blocks per page = Page size / Min block size\n=> log2(Max num_block per page) = log2(Page size / Min block size)\n\t\t\t\t= log2(Page size) - log2(Min block size)\n\n=> Max db_l2nbperpage = L2PSIZE - L2MINBLOCKSIZE","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","score":7.1},"cwes":["CWE-125"],"references":["https://git.kernel.org/stable/c/11509910c599cbd04585ec35a6d5e1a0053d84c1","https://git.kernel.org/stable/c/2a03c4e683d33d17b667418eb717b13dda1fac6b","https://git.kernel.org/stable/c/47b7eaae08e8b2f25bdf37bc14d21be090bcb20f","https://git.kernel.org/stable/c/8c1efe3f74a7864461b0dff281c5562154b4aa8e","https://git.kernel.org/stable/c/a4855aeb13e4ad1f23e16753b68212e180f7d848"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:08:41.295252406+00:00"},"epss":{"cve":"CVE-2023-53222","score":0.00168,"percentile":0.06135,"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."]}