{"id":"CVE-2025-39793","summary":"io_uring/memmap: cast nr_pages to size_t before shifting","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/memmap: cast nr_pages to size_t before shifting\n\nIf the allocated size exceeds UINT_MAX, then it's necessary to cast\nthe mr-\u003enr_pages value to size_t to prevent it from overflowing. In\npractice this isn't much of a concern as the required memory size will\nhave been validated upfront, and accounted to the user. And \u003e 4GB sizes\nwill be necessary to make the lack of a cast a problem, which greatly\nexceeds normal user locked_vm settings that are generally in the kb to\nmb range. However, if root is used, then accounting isn't done, and\nthen it's possible to hit this issue.","modified":"2026-08-12T03:51:35.199125283Z","published":"2025-09-12T15:59:30.388Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39793.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/33503c083fda048c77903460ac0429e1e2c0e341"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a69a9b53c54e2d33e2a5b1ea4a9a71fd01c6cf3a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c6a2706e08b8a1b2d3740161c0977d38e596c1ee"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39793.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-39793"},{"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":"087f997870a948820ec366701d178f402c6a23a3"},{"fixed":"c6a2706e08b8a1b2d3740161c0977d38e596c1ee"},{"fixed":"a69a9b53c54e2d33e2a5b1ea4a9a71fd01c6cf3a"},{"fixed":"33503c083fda048c77903460ac0429e1e2c0e341"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-39793.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.14.0"},{"fixed":"6.15.11"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.16.0"},{"fixed":"6.16.2"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-39793.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}