{"id":"CVE-2026-93093","summary":"firmware: arm_scmi: Publish channel state before callbacks","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nfirmware: arm_scmi: Publish channel state before callbacks\n\nTransport setup can enable callbacks before the setup routine returns.\nmailbox_chan_setup() registers the mailbox client with\nmbox_request_channel(), and the mailbox controller startup path can enable\ninterrupt delivery before SCMI mailbox channel state has been published.\nSimilarly, smc_chan_setup() requests the optional A2P completion IRQ before\nthe SMC transport has made its cinfo pointer visible.\n\nIf a pending or spurious callback fires in those windows, the transport RX\ncallback can dereference a NULL transport cinfo pointer. Publishing only\nthe transport-private pointer is not sufficient either: an early callback\ncan enter the SCMI core before scmi_chan_setup() has assigned\ncinfo-\u003ehandle.\nThe core derives scmi_info from cinfo-\u003ehandle in the RX path, so a NULL\nhandle can still fault even when the transport-private cinfo is valid.\n\nAssign cinfo-\u003ehandle before invoking the transport setup callback. Publish\nthe mailbox and SMC transport-private channel state before requesting the\nmailbox channels or IRQ, and clear the early-published pointers again on\nsetup failure. Also unwind mailbox setup devres resources on failure so an\noptional RX setup error that is ignored by the core does not leave stale\ntransport state behind.","modified":"2026-09-19T03:47:31.473039837Z","published":"2026-09-17T16:11:08.360Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93093.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0314900dcdde044af0208fed212035dbfaa55843"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1bea027f7ef6fb889628b16c568a5f7c07a51b30"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6f3f532531e4a27d28a2240719d1b05ac11766c6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a1bc587568a4e373db76261dc9561dfc3653917f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93093.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93093"},{"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":"5c8a47a5a91d4d6e185f758d61997613d9c5d6ac"},{"fixed":"6f3f532531e4a27d28a2240719d1b05ac11766c6"},{"fixed":"1bea027f7ef6fb889628b16c568a5f7c07a51b30"},{"fixed":"a1bc587568a4e373db76261dc9561dfc3653917f"},{"fixed":"0314900dcdde044af0208fed212035dbfaa55843"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93093.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93093.json"}}],"schema_version":"1.9.0"}