{"id":"CVE-2026-90193","revision":"c56dbe7745634516a39a98718ad483b1","records":[{"revision":"c56dbe7745634516a39a98718ad483b1","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-90193","aliases":[],"title":"mailbox: qcom-cpucp: fix PREEMPT_RT self-deadlock in IRQ handler","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmailbox: qcom-cpucp: fix PREEMPT_RT self-deadlock in IRQ handler\n\nqcom_cpucp_mbox_irq_fn() calls mbox_chan_received_data() while holding\nchan->lock. Under PREEMPT_RT, spin_lock_irqsave() is converted to an\nrt_spinlock (rtmutex-based), which tracks ownership and can sleep.\n\nThe callback chain triggered by mbox_chan_received_data() eventually\nreaches mailbox_clear_channel() -> mbox_send_message() -> add_to_rbuf(),\nwhich attempts to re-acquire the same chan->lock. Since rtmutex detects\nthe re-entrant lock attempt by the same owner, the thread blocks waiting\nfor a lock it already holds, causing a permanent deadlock.\n\nThis deadlock manifests as 'irq/N-apss_cpucp_mbox' stuck in D state\nwith the following call trace:\n  rt_spin_lock -> mbox_send_message -> mailbox_clear_channel ->\n  scmi_rx_callback -> mbox_chan_received_data [<- held chan->lock here]\n\nFix by saving chan->cl locally and clearing the HW interrupt register\ninside the lock, then invoking mbox_chan_received_data() after releasing\nthe lock. This preserves the mutual exclusion for chan->cl access while\navoiding the lock re-entrancy that causes the PREEMPT_RT deadlock.","state":0,"publishedAt":"2026-09-17T16:07:13.672+00:00","modifiedAt":"2026-10-19T08:59:29.783+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/mailbox/qcom-cpucp-mbox.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"0e2a9a03106cd5fa0dbc9047675e7645c55e2669\",\n                            \"lessThan\": \"aa482273f32117c3adeba9b1cc945e0b5d33722d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"0e2a9a03106cd5fa0dbc9047675e7645c55e2669\",\n                            \"lessThan\": \"8b8de6400c86937ed57d680d06d716e167b381de\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"0e2a9a03106cd5fa0dbc9047675e7645c55e2669\",\n                            \"lessThan\": \"e40b3edeaf25cd09e9c88edb1ef99373ca37593b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"0e2a9a03106cd5fa0dbc9047675e7645c55e2669\",\n                            \"lessThan\": \"3690aaa6d18f6775c3e7932fb8af8c5bf6a6b69c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/mailbox/qcom-cpucp-mbox.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.11\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.11\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.110\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.52\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.6\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/aa482273f32117c3adeba9b1cc945e0b5d33722d","https://git.kernel.org/stable/c/8b8de6400c86937ed57d680d06d716e167b381de","https://git.kernel.org/stable/c/e40b3edeaf25cd09e9c88edb1ef99373ca37593b","https://git.kernel.org/stable/c/3690aaa6d18f6775c3e7932fb8af8c5bf6a6b69c"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-90193","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-90193","identifiers":["CVE-2026-90193"]},"retained":false,"historicalAffected":[]}],"coverage":[]}