{"id":"CVE-2026-93093","title":"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 ma…","summary":"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 ma…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 5c8a47a5a91d4d6e185f758d61997613d9c5d6ac < 6f3f532531e4a27d28a2240719d1b05ac11766c6","Linux >= 5c8a47a5a91d4d6e185f758d61997613d9c5d6ac < 1bea027f7ef6fb889628b16c568a5f7c07a51b30","Linux >= 5c8a47a5a91d4d6e185f758d61997613d9c5d6ac < a1bc587568a4e373db76261dc9561dfc3653917f","Linux >= 5c8a47a5a91d4d6e185f758d61997613d9c5d6ac < 0314900dcdde044af0208fed212035dbfaa55843","Linux 5.7"],"published":"2026-09-17","updated":"2026-09-17","sourceUpdated":"2026-09-17T17:18:03.300","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-93093","references":[{"url":"https://git.kernel.org/stable/c/0314900dcdde044af0208fed212035dbfaa55843","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/1bea027f7ef6fb889628b16c568a5f7c07a51b30","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6f3f532531e4a27d28a2240719d1b05ac11766c6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a1bc587568a4e373db76261dc9561dfc3653917f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-17T16:21:47.759Z","epss":0.00168,"epssPercentile":0.06449,"slug":"CVE-2026-93093","body":"## Overview\n\nIn 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->handle.\nThe core derives scmi_info from cinfo->handle in the RX path, so a NULL\nhandle can still fault even when the transport-private cinfo is valid.\n\nAssign cinfo->handle 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}