{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-23253", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:45.990Z", "datePublished": "2026-03-18T17:01:44.126Z", "dateUpdated": "2026-08-05T12:20:57.385Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:20:57.385Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: dvb-core: fix wrong reinitialization of ringbuffer on reopen\n\ndvb_dvr_open() calls dvb_ringbuffer_init() when a new reader opens the\nDVR device. dvb_ringbuffer_init() calls init_waitqueue_head(), which\nreinitializes the waitqueue list head to empty.\n\nSince dmxdev->dvr_buffer.queue is a shared waitqueue (all opens of the\nsame DVR device share it), this orphans any existing waitqueue entries\nfrom io_uring poll or epoll, leaving them with stale prev/next pointers\nwhile the list head is reset to {self, self}.\n\nThe waitqueue and spinlock in dvr_buffer are already properly\ninitialized once in dvb_dmxdev_init(). The open path only needs to\nreset the buffer data pointer, size, and read/write positions.\n\nReplace the dvb_ringbuffer_init() call in dvb_dvr_open() with direct\nassignment of data/size and a call to dvb_ringbuffer_reset(), which\nproperly resets pread, pwrite, and error with correct memory ordering\nwithout touching the waitqueue or spinlock." } ], "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 vulnerability is in the DVB DVR device driver, accessible via opening /dev/dvb/adapter*/dvr* character device files. This requires local system access.\nAC:L - The attacker controls both sides of the race — closing a DVR fd from one thread while reopening it from another. The attacker can reliably trigger the waitqueue reinitialization while stale entries exist.\nPR:L - DVB device files are typically accessible to local users (e.g., via \"video\" group membership). On Android phones, set-top boxes, and embedded media devices, the device user has access to DVB hardware. No elevated privileges are required.\nUI:N - No user interaction is needed. The attacker can open, poll, close, and reopen the DVR device entirely on their own.\nS:U - The vulnerability operates within the kernel's security authority. There is no crossing of security boundaries like VM escape or IOMMU bypass.\nC:H - The waitqueue list corruption creates orphaned entries with stale pointers, which is a use-after-free primitive. UAF gives the attacker control over freed memory contents, enabling arbitrary kernel memory reads.\nI:H - The list corruption from the orphaned waitqueue entries provides write primitives through stale prev/next pointer manipulation. This is a classic kernel list corruption that can be leveraged for arbitrary write and code execution via heap spraying.\nA:H - The stale list pointers will cause a kernel crash/oops when the orphaned wait_queue_entry is removed, as it dereferences corrupted prev/next pointers. This was confirmed by syzbot." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/media/dvb-core/dmxdev.c" ], "versions": [ { "version": "34731df288a5ffe4b0c396caf8cd24c6a710a222", "lessThan": "527cfa8a3486b3555c5c15e2f62be484a11398dc", "status": "affected", "versionType": "git" }, { "version": "34731df288a5ffe4b0c396caf8cd24c6a710a222", "lessThan": "fb378cf89be434ed1f10ab79cc4788fba8ae868d", "status": "affected", "versionType": "git" }, { "version": "34731df288a5ffe4b0c396caf8cd24c6a710a222", "lessThan": "f1e520ca2e83ece6731af6167c9e5e16931ecba0", "status": "affected", "versionType": "git" }, { "version": "34731df288a5ffe4b0c396caf8cd24c6a710a222", "lessThan": "af050ab44fa1b1897a940d7d756e512232f5e5df", "status": "affected", "versionType": "git" }, { "version": "34731df288a5ffe4b0c396caf8cd24c6a710a222", "lessThan": "d71781bad59b1c9d60d7068004581f9bf19c0c9d", "status": "affected", "versionType": "git" }, { "version": "34731df288a5ffe4b0c396caf8cd24c6a710a222", "lessThan": "cfd94642025e6f71c8f754bdec0800ee95e4f3dd", "status": "affected", "versionType": "git" }, { "version": "34731df288a5ffe4b0c396caf8cd24c6a710a222", "lessThan": "32eb8e4adc207ef31bc6e5ae56bab940b0176066", "status": "affected", "versionType": "git" }, { "version": "34731df288a5ffe4b0c396caf8cd24c6a710a222", "lessThan": "bfbc0b5b32a8f28ce284add619bf226716a59bc0", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/media/dvb-core/dmxdev.c" ], "versions": [ { "version": "2.6.17", "status": "affected" }, { "version": "0", "lessThan": "2.6.17", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.253", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.203", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.167", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.130", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.77", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.17", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.7", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "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": "2.6.17", "versionEndExcluding": "5.10.253" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "5.15.203" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "6.1.167" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "6.6.130" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "6.12.77" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "6.18.17" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "6.19.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/527cfa8a3486b3555c5c15e2f62be484a11398dc" }, { "url": "https://git.kernel.org/stable/c/fb378cf89be434ed1f10ab79cc4788fba8ae868d" }, { "url": "https://git.kernel.org/stable/c/f1e520ca2e83ece6731af6167c9e5e16931ecba0" }, { "url": "https://git.kernel.org/stable/c/af050ab44fa1b1897a940d7d756e512232f5e5df" }, { "url": "https://git.kernel.org/stable/c/d71781bad59b1c9d60d7068004581f9bf19c0c9d" }, { "url": "https://git.kernel.org/stable/c/cfd94642025e6f71c8f754bdec0800ee95e4f3dd" }, { "url": "https://git.kernel.org/stable/c/32eb8e4adc207ef31bc6e5ae56bab940b0176066" }, { "url": "https://git.kernel.org/stable/c/bfbc0b5b32a8f28ce284add619bf226716a59bc0" } ], "title": "media: dvb-core: fix wrong reinitialization of ringbuffer on reopen", "x_generator": { "engine": "bippy-1.2.0" } } } }