{"cve":"CVE-2025-37858","nvd":{"published":"2025-05-09T07:16:06.827","modified":"2026-06-17T09:15:34.747","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/jfs: Prevent integer overflow in AG size calculation\n\nThe JFS filesystem calculates allocation group (AG) size using 1 <<\nl2agsize in dbExtendFS(). When l2agsize exceeds 31 (possible with >2TB\naggregates on 32-bit systems), this 32-bit shift operation causes undefined\nbehavior and improper AG sizing.\n\nOn 32-bit architectures:\n- Left-shifting 1 by 32+ bits results in 0 due to integer overflow\n- This creates invalid AG sizes (0 or garbage values) in\nsbi->bmap->db_agsize\n- Subsequent block allocations would reference invalid AG structures\n- Could lead to:\n  - Filesystem corruption during extend operations\n  - Kernel crashes due to invalid memory accesses\n  - Security vulnerabilities via malformed on-disk structures\n\nFix by casting to s64 before shifting:\nbmp->db_agsize = (s64)1 << l2agsize;\n\nThis ensures 64-bit arithmetic even on 32-bit architectures. The cast\nmatches the data type of db_agsize (s64) and follows similar patterns in\nJFS block calculation code.\n\nFound by Linux Verification Center (linuxtesting.org) with SVACE.","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-190"],"references":["https://git.kernel.org/stable/c/211ed8f5e39e61f9e4d18edd64ce8005a67a1b2a","https://git.kernel.org/stable/c/3d8a45f87010a802aa214bf39702ca9d99cbf3ba","https://git.kernel.org/stable/c/55edbf5dbf60a8195c21e92124c4028939ae16b2","https://git.kernel.org/stable/c/7ccf3b35274512b60ecb614e0637e76bd6f2d829","https://git.kernel.org/stable/c/7fcbf789629cdb9fbf4e2172ce31136cfed11e5e"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:01:22.920403922+00:00"},"epss":{"cve":"CVE-2025-37858","score":0.00314,"percentile":0.24342,"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."]}