{"id":"CVE-2025-40305","summary":"9p/trans_fd: p9_fd_request: kick rx thread if EPOLLIN","details":"In the Linux kernel, the following vulnerability has been resolved:\n\n9p/trans_fd: p9_fd_request: kick rx thread if EPOLLIN\n\np9_read_work() doesn't set Rworksched and doesn't do schedule_work(m-\u003erq)\nif list_empty(&m-\u003ereq_list).\n\nHowever, if the pipe is full, we need to read more data and this used to\nwork prior to commit aaec5a95d59615 (\"pipe_read: don't wake up the writer\nif the pipe is still full\").\n\np9_read_work() does p9_fd_read() -\u003e ... -\u003e anon_pipe_read() which (before\nthe commit above) triggered the unnecessary wakeup. This wakeup calls\np9_pollwake() which kicks p9_poll_workfn() -\u003e p9_poll_mux(), p9_poll_mux()\nwill notice EPOLLIN and schedule_work(&m-\u003erq).\n\nThis no longer happens after the optimization above, change p9_fd_request()\nto use p9_poll_mux() instead of only checking for EPOLLOUT.","modified":"2026-03-20T12:43:15.389234Z","published":"2025-12-08T00:46:30.327Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40305.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/242531004d7de8c159f9bfadebe33fe8060b1046"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e8fe3f07a357c39d429e02ca34f740692d88967a"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40305.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-40305"},{"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":"aaec5a95d59615523db03dd53c2052f0a87beea7"},{"fixed":"242531004d7de8c159f9bfadebe33fe8060b1046"},{"fixed":"e8fe3f07a357c39d429e02ca34f740692d88967a"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-40305.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.14.0"},{"fixed":"6.17.8"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-40305.json"}}],"schema_version":"1.7.5"}