{"id":"CVE-2026-93093","state":"PUBLISHED","title":"firmware: arm_scmi: Publish channel state before callbacks","description":"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->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.","publishedAt":"2026-09-17T16:11:08.360Z","updatedAt":"2026-10-30T12:35:57.144Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5c8a47a5a91d4d6e185f758d61997613d9c5d6ac","status":"affected","lessThan":"9d349c7b2392b1196e10421421ea9a09fcc5d3cc","versionType":"git"},{"version":"5c8a47a5a91d4d6e185f758d61997613d9c5d6ac","status":"affected","lessThan":"50e38091a657ad81385e2aea7e2575e17ac23d79","versionType":"git"},{"version":"5c8a47a5a91d4d6e185f758d61997613d9c5d6ac","status":"affected","lessThan":"6f3f532531e4a27d28a2240719d1b05ac11766c6","versionType":"git"},{"version":"5c8a47a5a91d4d6e185f758d61997613d9c5d6ac","status":"affected","lessThan":"1bea027f7ef6fb889628b16c568a5f7c07a51b30","versionType":"git"},{"version":"5c8a47a5a91d4d6e185f758d61997613d9c5d6ac","status":"affected","lessThan":"a1bc587568a4e373db76261dc9561dfc3653917f","versionType":"git"},{"version":"5c8a47a5a91d4d6e185f758d61997613d9c5d6ac","status":"affected","lessThan":"0314900dcdde044af0208fed212035dbfaa55843","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/firmware/arm_scmi/driver.c","drivers/firmware/arm_scmi/transports/mailbox.c","drivers/firmware/arm_scmi/transports/smc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.7","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/firmware/arm_scmi/driver.c","drivers/firmware/arm_scmi/transports/mailbox.c","drivers/firmware/arm_scmi/transports/smc.c"]}],"references":["https://git.kernel.org/stable/c/9d349c7b2392b1196e10421421ea9a09fcc5d3cc","https://git.kernel.org/stable/c/50e38091a657ad81385e2aea7e2575e17ac23d79","https://git.kernel.org/stable/c/6f3f532531e4a27d28a2240719d1b05ac11766c6","https://git.kernel.org/stable/c/1bea027f7ef6fb889628b16c568a5f7c07a51b30","https://git.kernel.org/stable/c/a1bc587568a4e373db76261dc9561dfc3653917f","https://git.kernel.org/stable/c/0314900dcdde044af0208fed212035dbfaa55843"],"weaknesses":[],"ingestedAt":"2026-10-30T12:54:04.478Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/93xxx/CVE-2026-93093.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-93093","state":"PUBLISHED","datePublished":"2026-09-17T16:11:08.360Z","dateUpdated":"2026-10-30T12:35:57.144Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-17T16:02:15.084Z"},"containers":{"cna":{"title":"firmware: arm_scmi: Publish channel state before callbacks","descriptions":[{"lang":"en","value":"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->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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5c8a47a5a91d4d6e185f758d61997613d9c5d6ac","status":"affected","lessThan":"9d349c7b2392b1196e10421421ea9a09fcc5d3cc","versionType":"git"},{"version":"5c8a47a5a91d4d6e185f758d61997613d9c5d6ac","status":"affected","lessThan":"50e38091a657ad81385e2aea7e2575e17ac23d79","versionType":"git"},{"version":"5c8a47a5a91d4d6e185f758d61997613d9c5d6ac","status":"affected","lessThan":"6f3f532531e4a27d28a2240719d1b05ac11766c6","versionType":"git"},{"version":"5c8a47a5a91d4d6e185f758d61997613d9c5d6ac","status":"affected","lessThan":"1bea027f7ef6fb889628b16c568a5f7c07a51b30","versionType":"git"},{"version":"5c8a47a5a91d4d6e185f758d61997613d9c5d6ac","status":"affected","lessThan":"a1bc587568a4e373db76261dc9561dfc3653917f","versionType":"git"},{"version":"5c8a47a5a91d4d6e185f758d61997613d9c5d6ac","status":"affected","lessThan":"0314900dcdde044af0208fed212035dbfaa55843","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/firmware/arm_scmi/driver.c","drivers/firmware/arm_scmi/transports/mailbox.c","drivers/firmware/arm_scmi/transports/smc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.7","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/firmware/arm_scmi/driver.c","drivers/firmware/arm_scmi/transports/mailbox.c","drivers/firmware/arm_scmi/transports/smc.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/9d349c7b2392b1196e10421421ea9a09fcc5d3cc"},{"url":"https://git.kernel.org/stable/c/50e38091a657ad81385e2aea7e2575e17ac23d79"},{"url":"https://git.kernel.org/stable/c/6f3f532531e4a27d28a2240719d1b05ac11766c6"},{"url":"https://git.kernel.org/stable/c/1bea027f7ef6fb889628b16c568a5f7c07a51b30"},{"url":"https://git.kernel.org/stable/c/a1bc587568a4e373db76261dc9561dfc3653917f"},{"url":"https://git.kernel.org/stable/c/0314900dcdde044af0208fed212035dbfaa55843"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:35:57.144Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"6.18.52"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}