{"api_version":"1","generated_at":"2026-09-24T19:16:15+00:00","cve":"CVE-2026-89835","urls":{"html":"https://cve.report/CVE-2026-89835","api":"https://cve.report/api/cve/CVE-2026-89835.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89835","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89835"},"summary":{"title":"f2fs: avoid NULL checkpoint thread access in sysfs","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: avoid NULL checkpoint thread access in sysfs\n\ncheckpoint_merge can be enabled even when no checkpoint merge thread is\nrunning. A read-only mount is one case: f2fs does not start\nf2fs_issue_ckpt there, but ckpt_thread_ioprio is still writable through\nsysfs.\n\nThe ckpt_thread_ioprio store path updates the saved ioprio value and,\nwhen checkpoint_merge is enabled, calls set_task_ioprio() for the\ncheckpoint thread. If cprc->f2fs_issue_ckpt is NULL, that dereferences a\nNULL task pointer.\n\nProtect ckpt_thread_ioprio sysfs writes with s_umount as well, so the\ncheckpoint thread cannot disappear under the store path while updating\nits ioprio.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-16 11:16:50","updated_at":"2026-09-16 11:16:50"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/8f3b99c50dd0da1777994ce7c7e60d39b9f60f4b","name":"https://git.kernel.org/stable/c/8f3b99c50dd0da1777994ce7c7e60d39b9f60f4b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5cb33b00c8fbb6e8f1fa3d281c3036d5f7c7c41f","name":"https://git.kernel.org/stable/c/5cb33b00c8fbb6e8f1fa3d281c3036d5f7c7c41f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/aefcec3bebdeed2bff444378122300763325ba23","name":"https://git.kernel.org/stable/c/aefcec3bebdeed2bff444378122300763325ba23","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a6573f3ffc19542de9ebc1a2b1f930fd48ba538c","name":"https://git.kernel.org/stable/c/a6573f3ffc19542de9ebc1a2b1f930fd48ba538c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89835","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89835","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e65920661708b7c0f3db45c9cd5d0095034ee37f a6573f3ffc19542de9ebc1a2b1f930fd48ba538c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e65920661708b7c0f3db45c9cd5d0095034ee37f aefcec3bebdeed2bff444378122300763325ba23 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e65920661708b7c0f3db45c9cd5d0095034ee37f 8f3b99c50dd0da1777994ce7c7e60d39b9f60f4b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e65920661708b7c0f3db45c9cd5d0095034ee37f 5cb33b00c8fbb6e8f1fa3d281c3036d5f7c7c41f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.12","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.12 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.110 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.51 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.5 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/f2fs/sysfs.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"a6573f3ffc19542de9ebc1a2b1f930fd48ba538c","status":"affected","version":"e65920661708b7c0f3db45c9cd5d0095034ee37f","versionType":"git"},{"lessThan":"aefcec3bebdeed2bff444378122300763325ba23","status":"affected","version":"e65920661708b7c0f3db45c9cd5d0095034ee37f","versionType":"git"},{"lessThan":"8f3b99c50dd0da1777994ce7c7e60d39b9f60f4b","status":"affected","version":"e65920661708b7c0f3db45c9cd5d0095034ee37f","versionType":"git"},{"lessThan":"5cb33b00c8fbb6e8f1fa3d281c3036d5f7c7c41f","status":"affected","version":"e65920661708b7c0f3db45c9cd5d0095034ee37f","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/f2fs/sysfs.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.12"},{"lessThan":"5.12","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.110","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.51","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.110","versionStartIncluding":"5.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.51","versionStartIncluding":"5.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.5","versionStartIncluding":"5.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"5.12","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: avoid NULL checkpoint thread access in sysfs\n\ncheckpoint_merge can be enabled even when no checkpoint merge thread is\nrunning. A read-only mount is one case: f2fs does not start\nf2fs_issue_ckpt there, but ckpt_thread_ioprio is still writable through\nsysfs.\n\nThe ckpt_thread_ioprio store path updates the saved ioprio value and,\nwhen checkpoint_merge is enabled, calls set_task_ioprio() for the\ncheckpoint thread. If cprc->f2fs_issue_ckpt is NULL, that dereferences a\nNULL task pointer.\n\nProtect ckpt_thread_ioprio sysfs writes with s_umount as well, so the\ncheckpoint thread cannot disappear under the store path while updating\nits ioprio."}],"providerMetadata":{"dateUpdated":"2026-09-16T10:31:08.636Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/a6573f3ffc19542de9ebc1a2b1f930fd48ba538c"},{"url":"https://git.kernel.org/stable/c/aefcec3bebdeed2bff444378122300763325ba23"},{"url":"https://git.kernel.org/stable/c/8f3b99c50dd0da1777994ce7c7e60d39b9f60f4b"},{"url":"https://git.kernel.org/stable/c/5cb33b00c8fbb6e8f1fa3d281c3036d5f7c7c41f"}],"title":"f2fs: avoid NULL checkpoint thread access in sysfs","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89835","datePublished":"2026-09-16T10:31:08.636Z","dateReserved":"2026-09-11T19:38:34.769Z","dateUpdated":"2026-09-16T10:31:08.636Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-16 11:16:50","lastModifiedDate":"2026-09-16 11:16:50","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89835","Ordinal":"1","Title":"f2fs: avoid NULL checkpoint thread access in sysfs","CVE":"CVE-2026-89835","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89835","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: avoid NULL checkpoint thread access in sysfs\n\ncheckpoint_merge can be enabled even when no checkpoint merge thread is\nrunning. A read-only mount is one case: f2fs does not start\nf2fs_issue_ckpt there, but ckpt_thread_ioprio is still writable through\nsysfs.\n\nThe ckpt_thread_ioprio store path updates the saved ioprio value and,\nwhen checkpoint_merge is enabled, calls set_task_ioprio() for the\ncheckpoint thread. If cprc->f2fs_issue_ckpt is NULL, that dereferences a\nNULL task pointer.\n\nProtect ckpt_thread_ioprio sysfs writes with s_umount as well, so the\ncheckpoint thread cannot disappear under the store path while updating\nits ioprio.","Type":"Description","Title":"f2fs: avoid NULL checkpoint thread access in sysfs"}]}}}