{"id":"CVE-2026-98900","summary":"xen/gntalloc: validate grant count before allocation","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nxen/gntalloc: validate grant count before allocation\n\ngntalloc_ioctl_alloc() allocates the grant-id array before checking\nwhether the requested count fits within the global grant limit. Counts\nabove that limit cannot succeed, so reject them before the\nuser-controlled allocation reaches kcalloc().\n\nUse a subtraction-based check while holding gref_mutex so adding the\nrequested count cannot wrap. Also cast the count before advancing the\nper-file index so the page-size multiplication is performed in 64-bit\narithmetic.","modified":"2026-10-28T02:34:40.472059984Z","published":"2026-10-23T11:54:10.566Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98900.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2299822f3f466b5dcad2377bf63986199f881a6b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/231542f4e43cf9837cb520664545e85fbe666b7b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/641de086a05f349de7fc548612432bc2fed721ca"},{"type":"WEB","url":"https://git.kernel.org/stable/c/71a0cf87e19fb35c4292ca88985e376e613c900a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/720554c04acba80018ded069d3e0984bebaee891"},{"type":"WEB","url":"https://git.kernel.org/stable/c/84d5727cef8eb9c8a28210ad248f1c70b223b065"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e2806390aa1c4d5b3f7a68f10a56ae12c71c00d8"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98900.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98900"},{"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":"dd3140588d9551235ebc2a0dacdca098e7677573"},{"fixed":"e2806390aa1c4d5b3f7a68f10a56ae12c71c00d8"},{"fixed":"71a0cf87e19fb35c4292ca88985e376e613c900a"},{"fixed":"641de086a05f349de7fc548612432bc2fed721ca"},{"fixed":"720554c04acba80018ded069d3e0984bebaee891"},{"fixed":"84d5727cef8eb9c8a28210ad248f1c70b223b065"},{"fixed":"231542f4e43cf9837cb520664545e85fbe666b7b"},{"fixed":"2299822f3f466b5dcad2377bf63986199f881a6b"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-98900.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.39"},{"fixed":"5.10.271"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.222"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.189"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.158"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.111"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.53"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-98900.json"}}],"schema_version":"1.9.2"}