{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-98821 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-98821 is a vulnerability in Linux, published on 18 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-98821 and fix it if it is affected.\n\nWhat it is: CVE-2026-98821 is a vulnerability in Linux, published on 18 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-98821 in the wild and no public exploit code.\n\nAffected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-98821/ (Markdown: https://insights.sbomify.com/CVE-2026-98821/index.md)","id":"CVE-2026-98821","markdown":"https://insights.sbomify.com/CVE-2026-98821/index.md","name":"CVE-2026-98821","record":{"aliases":["BELL-CVE-2026-98821","DEBIAN-CVE-2026-98821","GHSA-4mqf-mrhr-h3rh","UBUNTU-CVE-2026-98821"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel block layer","requires_auth":"low_privilege","summary":"A local attacker can trigger a kernel crash via null pointer dereference in the block layer when using polled direct I/O with integrity metadata.","user_interaction":"not_required","vuln_class":"null_dereference"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nblock: reject polled dio with user integrity metadata\n\nIOCB_HAS_METADATA leaves iocb-\u003eprivate as a uio_meta, while\niocb_bio_iopoll() expects a bio. Since 2729a60bbfb9, metadata I/O\nalways uses __blkdev_direct_IO(), which never publishes the bio for\npolling, so IOPOLL calls bio_poll() on the uio_meta.\n\nReproducer: io_uring IOPOLL plus a PI attribute on an integrity device\n(scsi_debug dif=1 dix=1). KASAN reports:\n\n  Oops: general protection fault, probably for non-canonical\n  address 0xdffffc0000000004\n  KASAN: null-ptr-deref in range\n  [0x0000000000000020-0x0000000000000027]\n  RIP: 0010:bio_poll+0x9d/0x4b0\n  Call Trace:\n   iocb_bio_iopoll+0x5b/0x80\n   io_uring_classic_poll+0xf3/0x140\n   io_do_iopoll+0x4e3/0xc00\n   io_iopoll_check+0x275/0x560\n   __do_sys_io_uring_enter+0x2e5/0x720\n\nReturn -EOPNOTSUPP when HIPRI is combined with user metadata.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"block: reject polled dio with user integrity metadata","id":"CVE-2026-98821","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"null_dereference","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"wifi: mac80211: prevent AP VLAN tx from other interfaces","id":"CVE-2026-98822"},"packages":[],"prev":{"headline":"blk-mq: set RQF_USE_SCHED when the operation is known","id":"CVE-2026-98820"},"products":["Linux"],"published":"2026-10-18","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A local attacker can trigger a kernel crash via null pointer dereference in the block layer when using polled direct I/O with integrity metadata.","url":"https://insights.sbomify.com/CVE-2026-98821/"}