{"id":"CVE-2026-98900","state":"PUBLISHED","title":"xen/gntalloc: validate grant count before allocation","description":"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.","publishedAt":"2026-10-23T11:54:10.566Z","updatedAt":"2026-10-26T06:56:27.943Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"e2806390aa1c4d5b3f7a68f10a56ae12c71c00d8","versionType":"git"},{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"71a0cf87e19fb35c4292ca88985e376e613c900a","versionType":"git"},{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"641de086a05f349de7fc548612432bc2fed721ca","versionType":"git"},{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"720554c04acba80018ded069d3e0984bebaee891","versionType":"git"},{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"84d5727cef8eb9c8a28210ad248f1c70b223b065","versionType":"git"},{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"231542f4e43cf9837cb520664545e85fbe666b7b","versionType":"git"},{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"2299822f3f466b5dcad2377bf63986199f881a6b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/xen/gntalloc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.39","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.39","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/xen/gntalloc.c"]}],"references":["https://git.kernel.org/stable/c/e2806390aa1c4d5b3f7a68f10a56ae12c71c00d8","https://git.kernel.org/stable/c/71a0cf87e19fb35c4292ca88985e376e613c900a","https://git.kernel.org/stable/c/641de086a05f349de7fc548612432bc2fed721ca","https://git.kernel.org/stable/c/720554c04acba80018ded069d3e0984bebaee891","https://git.kernel.org/stable/c/84d5727cef8eb9c8a28210ad248f1c70b223b065","https://git.kernel.org/stable/c/231542f4e43cf9837cb520664545e85fbe666b7b","https://git.kernel.org/stable/c/2299822f3f466b5dcad2377bf63986199f881a6b"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98900.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98900","state":"PUBLISHED","datePublished":"2026-10-23T11:54:10.566Z","dateUpdated":"2026-10-26T06:56:27.943Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.379Z"},"containers":{"cna":{"title":"xen/gntalloc: validate grant count before allocation","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"e2806390aa1c4d5b3f7a68f10a56ae12c71c00d8","versionType":"git"},{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"71a0cf87e19fb35c4292ca88985e376e613c900a","versionType":"git"},{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"641de086a05f349de7fc548612432bc2fed721ca","versionType":"git"},{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"720554c04acba80018ded069d3e0984bebaee891","versionType":"git"},{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"84d5727cef8eb9c8a28210ad248f1c70b223b065","versionType":"git"},{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"231542f4e43cf9837cb520664545e85fbe666b7b","versionType":"git"},{"version":"dd3140588d9551235ebc2a0dacdca098e7677573","status":"affected","lessThan":"2299822f3f466b5dcad2377bf63986199f881a6b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/xen/gntalloc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.39","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.39","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/xen/gntalloc.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/e2806390aa1c4d5b3f7a68f10a56ae12c71c00d8"},{"url":"https://git.kernel.org/stable/c/71a0cf87e19fb35c4292ca88985e376e613c900a"},{"url":"https://git.kernel.org/stable/c/641de086a05f349de7fc548612432bc2fed721ca"},{"url":"https://git.kernel.org/stable/c/720554c04acba80018ded069d3e0984bebaee891"},{"url":"https://git.kernel.org/stable/c/84d5727cef8eb9c8a28210ad248f1c70b223b065"},{"url":"https://git.kernel.org/stable/c/231542f4e43cf9837cb520664545e85fbe666b7b"},{"url":"https://git.kernel.org/stable/c/2299822f3f466b5dcad2377bf63986199f881a6b"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-26T06:56:27.943Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"5.10.271"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"5.15.222"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"6.1.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}