{"api_version":"1","generated_at":"2026-10-27T06:05:54+00:00","cve":"CVE-2026-90324","urls":{"html":"https://cve.report/CVE-2026-90324","api":"https://cve.report/api/cve/CVE-2026-90324.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-90324","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-90324"},"summary":{"title":"ublk: check import_ubuf() return value","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nublk: check import_ubuf() return value\n\nimport_ubuf() can fail if the address range (provided by the userspace\nublk server) is outside the allowed user address space. Return that 0\nbytes were copied if import_ubuf() fails rather than passing an\nuninitialized struct iov_iter to ublk_copy_user_pages().","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-17 17:17:30","updated_at":"2026-10-21 13:20:50"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/5ac6019cb78e98c9608fda72726b36ddf8474dd7","name":"https://git.kernel.org/stable/c/5ac6019cb78e98c9608fda72726b36ddf8474dd7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3831568792af75b6523fa93bb91560e29189cf55","name":"https://git.kernel.org/stable/c/3831568792af75b6523fa93bb91560e29189cf55","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/0121c84adb6a4cd6f7560b5895bd88f9899bbc1f","name":"https://git.kernel.org/stable/c/0121c84adb6a4cd6f7560b5895bd88f9899bbc1f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/27ff6e8703f7a7160c728501da2f8ef8e7bb6b2f","name":"https://git.kernel.org/stable/c/27ff6e8703f7a7160c728501da2f8ef8e7bb6b2f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7f97c762b5f6e0005c5c7d040ded73bf7fb3587e","name":"https://git.kernel.org/stable/c/7f97c762b5f6e0005c5c7d040ded73bf7fb3587e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-90324","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90324","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 981f95a571e3ca20a496c0b77dbf6b06039c6648 7f97c762b5f6e0005c5c7d040ded73bf7fb3587e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 981f95a571e3ca20a496c0b77dbf6b06039c6648 27ff6e8703f7a7160c728501da2f8ef8e7bb6b2f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 981f95a571e3ca20a496c0b77dbf6b06039c6648 0121c84adb6a4cd6f7560b5895bd88f9899bbc1f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 981f95a571e3ca20a496c0b77dbf6b06039c6648 5ac6019cb78e98c9608fda72726b36ddf8474dd7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 981f95a571e3ca20a496c0b77dbf6b06039c6648 3831568792af75b6523fa93bb91560e29189cf55 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.5","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.5 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.160 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.114 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.52 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.6 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"90324","cve":"CVE-2026-90324","epss":"0.001730000","percentile":"0.064150000","score_date":"2026-10-21","updated_at":"2026-10-22 00:15:10"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/block/ublk_drv.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"7f97c762b5f6e0005c5c7d040ded73bf7fb3587e","status":"affected","version":"981f95a571e3ca20a496c0b77dbf6b06039c6648","versionType":"git"},{"lessThan":"27ff6e8703f7a7160c728501da2f8ef8e7bb6b2f","status":"affected","version":"981f95a571e3ca20a496c0b77dbf6b06039c6648","versionType":"git"},{"lessThan":"0121c84adb6a4cd6f7560b5895bd88f9899bbc1f","status":"affected","version":"981f95a571e3ca20a496c0b77dbf6b06039c6648","versionType":"git"},{"lessThan":"5ac6019cb78e98c9608fda72726b36ddf8474dd7","status":"affected","version":"981f95a571e3ca20a496c0b77dbf6b06039c6648","versionType":"git"},{"lessThan":"3831568792af75b6523fa93bb91560e29189cf55","status":"affected","version":"981f95a571e3ca20a496c0b77dbf6b06039c6648","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/block/ublk_drv.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.5"},{"lessThan":"6.5","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.160","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.114","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.52","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.6","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.160","versionStartIncluding":"6.5","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.114","versionStartIncluding":"6.5","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.52","versionStartIncluding":"6.5","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.6","versionStartIncluding":"6.5","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3","versionStartIncluding":"6.5","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nublk: check import_ubuf() return value\n\nimport_ubuf() can fail if the address range (provided by the userspace\nublk server) is outside the allowed user address space. Return that 0\nbytes were copied if import_ubuf() fails rather than passing an\nuninitialized struct iov_iter to ublk_copy_user_pages()."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - The bad pointer is io->buf.addr from ublksrv_io_cmd.addr in ublk_ch_uring_cmd_local() on UBLK_IO_FETCH_REQ, UBLK_IO_COMMIT_AND_FETCH_REQ, or UBLK_IO_NEED_GET_DATA against /dev/ublkcN. import_ubuf() in ublk_map_io()/ublk_unmap_io() is handed that local userspace address; no network protocol carries it.\nAC:L - The ublk server chooses the FETCH/COMMIT buffer address. A non-zero kernel or wrap-around address fails access_ok() in import_ubuf() on every call (ublk_check_fetch_buf() only rejects addr==0). ublk_map_io()/ublk_unmap_io() then pass the uninitialized iov_iter to ublk_copy_user_pages() with no race or victim state.\nPR:L - ublk_ctrl_add_dev() lets a caller without CAP_SYS_ADMIN create a UBLK_F_UNPRIVILEGED_DEV device, and those devices cannot set UBLK_F_USER_COPY, UBLK_F_SUPPORT_ZERO_COPY, or UBLK_F_AUTO_BUF_REG, so ublk_need_map_io() is always true. ublk_ch_open() has no capability check; ublk_open() allows the owner to issue I/O to /dev/ublkbN.\nUI:N - The attacking process itself issues UBLK_CMD_ADD_DEV and UBLK_CMD_START_DEV on /dev/ublk-control, UBLK_IO_FETCH_REQ with the bad addr on /dev/ublkcN, then read/write on its own ublkb disk so ublk_queue_rq() → ublk_cmd_tw_cb() → ublk_dispatch_req() runs. No other user must mount or open anything.\nS:U - ublk_copy_user_pages() copies between the ublk request bio pages and the confused iov_iter entirely inside the host kernel via _copy_to_iter()/_copy_from_iter(). This is local kernel memory corruption, not a VM, IOMMU, or hypervisor escape.\nC:H - On a READ, ublk_unmap_io() calls _copy_from_iter() with the uninitialized iov_iter. iterate_and_advance() may treat leftover iter_type as ITER_KVEC or ITER_BVEC, so memcpy_from_iter() copies kernel memory into the request bio pages, which the attacker then reads from /dev/ublkbN.\nI:H - On a WRITE, ublk_map_io() calls _copy_to_iter() with that uninitialized iter, so iterate_kvec()/memcpy_to_iter() can write the attacker-controlled ublkb write payload to leftover kernel pointers. Garbage iter_type is iov_iter type confusion and an arbitrary kernel write.\nA:H - iterate_kvec() loads p->iov_len from leftover kvec pointers and iterate_bvec() calls kmap_local_page() on leftover bv_page, either of which oopses. ublk_unmap_io() also hits WARN_ON_ONCE(!data_source) in _copy_from_iter() when the iter was left with data_source==0."}]}],"providerMetadata":{"dateUpdated":"2026-10-21T12:50:58.953Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/7f97c762b5f6e0005c5c7d040ded73bf7fb3587e"},{"url":"https://git.kernel.org/stable/c/27ff6e8703f7a7160c728501da2f8ef8e7bb6b2f"},{"url":"https://git.kernel.org/stable/c/0121c84adb6a4cd6f7560b5895bd88f9899bbc1f"},{"url":"https://git.kernel.org/stable/c/5ac6019cb78e98c9608fda72726b36ddf8474dd7"},{"url":"https://git.kernel.org/stable/c/3831568792af75b6523fa93bb91560e29189cf55"}],"title":"ublk: check import_ubuf() return value","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-90324","datePublished":"2026-09-17T16:08:40.077Z","dateReserved":"2026-09-11T19:38:34.802Z","dateUpdated":"2026-10-21T12:50:58.953Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-17 17:17:30","lastModifiedDate":"2026-10-21 13:20:50","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"90324","Ordinal":"1","Title":"ublk: check import_ubuf() return value","CVE":"CVE-2026-90324","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"90324","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nublk: check import_ubuf() return value\n\nimport_ubuf() can fail if the address range (provided by the userspace\nublk server) is outside the allowed user address space. Return that 0\nbytes were copied if import_ubuf() fails rather than passing an\nuninitialized struct iov_iter to ublk_copy_user_pages().","Type":"Description","Title":"ublk: check import_ubuf() return value"}]}}}