{"id":"CVE-2026-74392","summary":"dm: limit target bio polling to one shot","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm: limit target bio polling to one shot\n\ndm_poll_bio() is the -\u003epoll_bio() callback for a stacked dm device.\nThe caller only knows about the dm queue, so it may decide to do a\nspinning poll if it thinks a single queue is being polled. Passing those\nflags unchanged to the mapped clone lets blk_mq_poll() spin on a target\nqueue from inside dm_poll_bio().\n\nWith io_uring IOPOLL on a dm-stripe target this can keep a task in\n\n  dm_poll_bio() -\u003e bio_poll() -\u003e blk_mq_poll()\n\nlong enough to trigger an RCU CPU stall, before io_uring gets back to\nio_iopoll_check() and its need_resched() check.\n\nKeep dm's -\u003epoll_bio() bounded by forcing one-shot polling for target\nbios. The caller can invoke dm_poll_bio() again if it wants to keep\npolling, and it also gets a chance to reap completions or reschedule\nbetween passes.","modified":"2026-08-18T03:31:27.329067202Z","published":"2026-08-15T05:59:05.787Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74392.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/5aa0f9231cbacade065cedd8e9b5ebd067231171"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6c4ede3b771adbb3bf21ad4e8b8f2f6f6120c4f7"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74392.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74392"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"f22ecf9c14c12918e30f2179ef516e99eb8b2e49"},{"fixed":"6c4ede3b771adbb3bf21ad4e8b8f2f6f6120c4f7"},{"fixed":"5aa0f9231cbacade065cedd8e9b5ebd067231171"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74392.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74392.json"}}],"schema_version":"1.9.0"}