{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89899", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.774Z", "datePublished": "2026-09-16T10:31:59.589Z", "dateUpdated": "2026-10-19T08:54:32.139Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:54:32.139Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: cec: disable delayed work before freeing an interrupted transmit\n\ncec_transmit_msg_fh() drops adap->lock to wait for a blocking transmit in\nwait_for_completion_killable(). If that wait is interrupted by a signal,\ncancel_delayed_work_sync() can run before the CEC kthread arms the reply\ntimeout via schedule_delayed_work(&data->work) in cec_transmit_done_ts().\nThe work is then armed after the cancel, and the data is freed with its\ndelayed_work still pending:\n\n ODEBUG: free active (active state 0) object: ... hint: cec_wait_timeout\n\nUse disable_delayed_work_sync(): it cancels the work and disables it, so\nthe later schedule_delayed_work() becomes a no-op and the work cannot be\nre-armed. The data is freed right after, so it need not be re-enabled." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The UAF is in cec_transmit_msg_fh(), reached only via the local CEC_TRANSMIT ioctl on /dev/cec* (cec_ioctl to cec_transmit). A CEC peer on the HDMI bus cannot signal-interrupt wait_for_completion_killable(), so this is Local, unlike CEC RX IRQ bugs scored Adjacent.\nAC:L - The attacker issues a blocking CEC_TRANSMIT with a reply timeout and signals their own thread so cancel_delayed_work_sync() races the CEC kthread arming data->work in cec_transmit_done_ts(). They control both sides and can retry; syzkaller triggered it.\nPR:L - cec_open() defaults to CEC_MODE_INITIATOR, and neither CEC_TRANSMIT nor CEC_ADAP_S_LOG_ADDRS calls capable(). Only raw mode needs CAP_SYS_RAWIO and monitor modes need CAP_NET_ADMIN, neither required here. Unprivileged users with /dev/cec (video group, uaccess, Android HDMI-CEC) can trigger it.\nUI:N - The attacker opens /dev/cec, configures logical addresses, issues the blocking transmit ioctl, and delivers a signal to their own process. No separate victim action is required.\nS:U - The use-after-free corrupts kernel heap (struct cec_data) in the host kernel. It does not cross a VM, IOMMU, or other separate security authority.\nC:H - cec_wait_timeout() runs on a kmalloc'd struct cec_data after kfree(), so a sprayed replacement object yields an attacker-controlled adap pointer and list walks. Per kernel CNA guidance, use-after-free is High confidentiality.\nI:H - The delayed-work UAF lets the attacker spray struct cec_data and corrupt list_heads and the adapter mutex when cec_wait_timeout()/cec_data_cancel() run, enabling arbitrary write and control-flow hijack. Per kernel CNA guidance, use-after-free is High integrity.\nA:H - Freeing struct cec_data while its delayed_work is still pending causes cec_wait_timeout() to run on freed memory, producing a kernel oops or panic even without a full exploit. Per kernel CNA guidance, use-after-free is High availability." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/media/cec/core/cec-adap.c" ], "versions": [ { "version": "490d84f6d73c12f4204241cff8651eed60aae914", "lessThan": "9a951931d4b4084acd64fa55fc3672a9da45ddf9", "status": "affected", "versionType": "git" }, { "version": "490d84f6d73c12f4204241cff8651eed60aae914", "lessThan": "a3adb63b121937b97f7fdc51e96564c7c799538b", "status": "affected", "versionType": "git" }, { "version": "490d84f6d73c12f4204241cff8651eed60aae914", "lessThan": "9c6ceb0949227c1f0cf0e19393daec72d9889871", "status": "affected", "versionType": "git" }, { "version": "490d84f6d73c12f4204241cff8651eed60aae914", "lessThan": "0fbd5c2327020858c45b2d1c65775d64cdeca523", "status": "affected", "versionType": "git" }, { "version": "e448dfd6d3ec944411f6575bc24e4f8baa1e297f", "status": "affected", "versionType": "git" }, { "version": "2781b86d7e45de09befa5ace296b66787146561f", "status": "affected", "versionType": "git" }, { "version": "4.18.19", "lessThan": "4.19", "status": "affected", "versionType": "semver" }, { "version": "4.19.2", "lessThan": "4.20", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/media/cec/core/cec-adap.c" ], "versions": [ { "version": "4.20", "status": "affected" }, { "version": "0", "lessThan": "4.20", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.51", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.5", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.18.51" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "7.2.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "7.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.18.19" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9a951931d4b4084acd64fa55fc3672a9da45ddf9" }, { "url": "https://git.kernel.org/stable/c/a3adb63b121937b97f7fdc51e96564c7c799538b" }, { "url": "https://git.kernel.org/stable/c/9c6ceb0949227c1f0cf0e19393daec72d9889871" }, { "url": "https://git.kernel.org/stable/c/0fbd5c2327020858c45b2d1c65775d64cdeca523" } ], "title": "media: cec: disable delayed work before freeing an interrupted transmit", "x_generator": { "engine": "bippy-1.2.0" } } } }