{"id":"CVE-2026-80811","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-80811","generatedAt":"2026-10-28T08:27:38.623Z","title":"In the Linux kernel, the following vulnerability has been resolved: io_uring/cmd: fix iovec leak when the async cmd is not recycled An io_async_cmd carries an iovec array in ->vec.iovec, allocated when the vec has to grow and kept across recycling…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/cmd: fix iovec leak when the async cmd is not recycled\n\nAn io_async_cmd carries an iovec array in ->vec.iovec, allocated when the\nvec has to grow and kept across recycling through ctx->cmd_cache.  On two\npaths nothing frees it and io_clean_op()'s kfree(req->async_data) drops\nthe io_async_cmd without it.\n\nio_req_uring_cleanup() clears the async data flags only when\nio_alloc_cache_put() succeeds, and the cache holds IO_ALLOC_CACHE_MAX ==\n128 entries, so once it is full the put fails and the vec is left behind.\nAn NVMe passthrough workload gets there without doing anything unusual:\nnvme_uring_cmd_io() returns -EIOCBQUEUED, so the io_async_cmd stays\nattached for the lifetime of the command and the live object count tracks\nthe queue depth.  Above 128 the puts start failing.\n\n->cleanup is the last chance to free an inherited vec, since\nio_req_uring_cleanup() returns early for an io-wq issued command and is\nnot called at all for one completed without ever being issued.  But\nio_clean_op() calls ->cleanup only if REQ_F_NEED_CLEANUP is set, and for\nuring_cmd that happens only where the vec has to grow, so a command\nreusing a large enough cached vec never sets it.  io_rw_alloc_async() and\nio_msg_alloc_async() flag an inherited vec for exactly this reason;\nio_uring_cmd_prep() does not.\n\nFlag an inherited vec in io_uring_cmd_prep(), and free the vec when the\ncache put fails, as io_req_rw_cleanup() does.\n\nThe leak is invisible under KASAN, where io_alloc_cache_vec_kasan() frees\nthe vec unconditionally.","published":"2026-09-04T16:18:08.000Z","lastModified":"2026-10-19T09:17:16.000Z","status":"Received","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":null,"cwe":[],"affected":[],"epss":{"score":0.00209,"percentile":0.10963,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"unknown","text":"Not yet scored. NVD analysis is pending; check back once CVSS and EPSS values are published."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/7068d3587a64a24943a7c9e232976da2c9e0e303","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b290de4d16d75b6c1ef42025b47f5d94eb1ec09f","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b6a768aa975b9ca81b92f028bdd975d1f8237894","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bb34ae5da3365699d53a756f4c96b6ea9f8ba0c1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80811","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}