{"id":"CVE-2026-23194","summary":"rust_binder: correctly handle FDA objects of length zero","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nrust_binder: correctly handle FDA objects of length zero\n\nFix a bug where an empty FDA (fd array) object with 0 fds would cause an\nout-of-bounds error. The previous implementation used `skip == 0` to\nmean \"this is a pointer fixup\", but 0 is also the correct skip length\nfor an empty FDA. If the FDA is at the end of the buffer, then this\nresults in an attempt to write 8-bytes out of bounds. This is caught and\nresults in an EINVAL error being returned to userspace.\n\nThe pattern of using `skip == 0` as a special value originates from the\nC-implementation of Binder. As part of fixing this bug, this pattern is\nreplaced with a Rust enum.\n\nI considered the alternate option of not pushing a fixup when the length\nis zero, but I think it's cleaner to just get rid of the zero-is-special\nstuff.\n\nThe root cause of this bug was diagnosed by Gemini CLI on first try. I\nused the following prompt:\n\n\u003e There appears to be a bug in @drivers/android/binder/thread.rs where\n\u003e the Fixups oob bug is triggered with 316 304 316 324. This implies\n\u003e that we somehow ended up with a fixup where buffer A has a pointer to\n\u003e buffer B, but the pointer is located at an index in buffer A that is\n\u003e out of bounds. Please investigate the code to find the bug. You may\n\u003e compare with @drivers/android/binder.c that implements this correctly.","modified":"2026-08-12T03:51:37.539922660Z","published":"2026-02-14T16:27:20.944Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23194.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/598fe3ff32e43918ed8a062f55432b3d23e6340c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8f589c9c3be539d6c2b393c82940c3783831082f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23194.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23194"},{"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":"eafedbc7c050c44744fbdf80bdf3315e860b7513"},{"fixed":"598fe3ff32e43918ed8a062f55432b3d23e6340c"},{"fixed":"8f589c9c3be539d6c2b393c82940c3783831082f"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23194.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"6.18.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23194.json"}}],"schema_version":"1.9.0"}