{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-35920", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-17T13:50:33.124Z", "datePublished": "2024-05-19T10:10:32.379Z", "dateUpdated": "2026-08-05T11:30:59.577Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:30:59.577Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: mediatek: vcodec: adding lock to protect decoder context list\n\nAdd a lock for the ctx_list, to avoid accessing a NULL pointer\nwithin the 'vpu_dec_ipi_handler' function when the ctx_list has\nbeen deleted due to an unexpected behavior on the SCP IP block.\n\nHardware name: Google juniper sku16 board (DT)\npstate: 20400005 (nzCv daif +PAN -UAO -TCO BTYPE=--)\npc : vpu_dec_ipi_handler+0x58/0x1f8 [mtk_vcodec_dec]\nlr : scp_ipi_handler+0xd0/0x194 [mtk_scp]\nsp : ffffffc0131dbbd0\nx29: ffffffc0131dbbd0 x28: 0000000000000000\nx27: ffffff9bb277f348 x26: ffffff9bb242ad00\nx25: ffffffd2d440d3b8 x24: ffffffd2a13ff1d4\nx23: ffffff9bb7fe85a0 x22: ffffffc0133fbdb0\nx21: 0000000000000010 x20: ffffff9b050ea328\nx19: ffffffc0131dbc08 x18: 0000000000001000\nx17: 0000000000000000 x16: ffffffd2d461c6e0\nx15: 0000000000000242 x14: 000000000000018f\nx13: 000000000000004d x12: 0000000000000000\nx11: 0000000000000001 x10: fffffffffffffff0\nx9 : ffffff9bb6e793a8 x8 : 0000000000000000\nx7 : 0000000000000000 x6 : 000000000000003f\nx5 : 0000000000000040 x4 : fffffffffffffff0\nx3 : 0000000000000020 x2 : ffffff9bb6e79080\nx1 : 0000000000000010 x0 : ffffffc0131dbc08\nCall trace:\nvpu_dec_ipi_handler+0x58/0x1f8 [mtk_vcodec_dec (HASH:6c3f 2)]\nscp_ipi_handler+0xd0/0x194 [mtk_scp (HASH:7046 3)]\nmt8183_scp_irq_handler+0x44/0x88 [mtk_scp (HASH:7046 3)]\nscp_irq_handler+0x48/0x90 [mtk_scp (HASH:7046 3)]\nirq_thread_fn+0x38/0x94\nirq_thread+0x100/0x1c0\nkthread+0x140/0x1fc\nret_from_fork+0x10/0x30\nCode: 54000088 f94ca50a eb14015f 54000060 (f9400108)\n---[ end trace ace43ce36cbd5c93 ]---\nKernel panic - not syncing: Oops: Fatal exception\nSMP: stopping secondary CPUs\nKernel Offset: 0x12c4000000 from 0xffffffc010000000\nPHYS_OFFSET: 0xffffffe580000000\nCPU features: 0x08240002,2188200c\nMemory Limit: none" } ], "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 vulnerable code is reached by opening/closing and driving the MediaTek V4L2 decoder node `/dev/videoN`, i.e. local syscalls on the device file. There is no network-facing path into `vpu_dec_check_ap_inst()`.\nAC:L - The attacker controls both sides of the race — an `open()`/`close()` loop mutates the shared `dev->ctx_list` while decode jobs it submitted drive the SCP IPI ACKs that enter the unlocked `list_for_each_entry()`. It can also deterministically widen the window by opening many contexts and by forcing the 2000 ms `scp_ipi_send()` ACK timeout so late ACKs arrive after the context was freed.\nPR:L - `fops_vcodec_open()` enforces no capability check; any local user with access to the `/dev/video*` node (video group, and the sandboxed media/GPU processes on ChromeOS and Android that routinely hold it) can reach it. No root or CAP_* privilege is needed.\nUI:N - The attacking process performs every step itself — opening the decoder, submitting a bitstream, and closing the fd concurrently. No victim action or interaction is required.\nS:U - The corruption and the vulnerable code are both in the kernel's own security authority; the SCP co-processor merely delivers the IPI that triggers it. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - The unlocked traversal reads `ctx->list.next` and `ctx->vpu_inst` out of a `mtk_vcodec_dec_ctx` that was just `kfree()`d, a use-after-free read of a reallocatable slab object. Heap grooming lets the attacker supply the link pointer, turning the loop into a controlled-address dereference usable for kernel memory disclosure.\nI:H - Because the staleness guard is racy, `vpu_dec_ipi_handler()` proceeds against a freed `vdec_vpu_inst` (freed with its containing `vdec_h264_inst`/`vdec_vp9_inst` in `fops_vcodec_release()`), writing `vpu->failure`, `vpu->signaled`, and on INIT_ACK `vpu->vsi`/`vpu->inst_addr`/`vpu->inst_id` into memory that may already be reallocated. That is a use-after-free write at fixed offsets, exploitable for cross-object corruption and control-flow hijack.\nA:H - The commit records a reproduced fatal oops in `vpu_dec_ipi_handler+0x58` ending in \"Kernel panic - not syncing: Oops: Fatal exception\" with secondary CPUs stopped. Any local user able to open the decoder node can trigger this repeatedly for a full system crash." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c", "drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c", "drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h", "drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c" ], "versions": [ { "version": "655b86e52eacdce79c2e02c5ec7258a97fcc2e4a", "lessThan": "0a2dc707aa42214f9c4827bd57e344e29a0841d6", "status": "affected", "versionType": "git" }, { "version": "655b86e52eacdce79c2e02c5ec7258a97fcc2e4a", "lessThan": "23aaf824121055ba81b55f75444355bd83c8eb38", "status": "affected", "versionType": "git" }, { "version": "655b86e52eacdce79c2e02c5ec7258a97fcc2e4a", "lessThan": "6467cda18c9f9b5f2f9a0aa1e2861c653e41f382", "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/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c", "drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c", "drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h", "drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c" ], "versions": [ { "version": "6.6", "status": "affected" }, { "version": "0", "lessThan": "6.6", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.27", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.8.6", "lessThanOrEqual": "6.8.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.9", "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": "6.6", "versionEndExcluding": "6.6.27" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.8.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.9" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0a2dc707aa42214f9c4827bd57e344e29a0841d6" }, { "url": "https://git.kernel.org/stable/c/23aaf824121055ba81b55f75444355bd83c8eb38" }, { "url": "https://git.kernel.org/stable/c/6467cda18c9f9b5f2f9a0aa1e2861c653e41f382" } ], "title": "media: mediatek: vcodec: adding lock to protect decoder context list", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2024-06-17T17:38:32.899934Z", "id": "CVE-2024-35920", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-17T17:41:01.161Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-02T03:21:49.045Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/0a2dc707aa42214f9c4827bd57e344e29a0841d6", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/23aaf824121055ba81b55f75444355bd83c8eb38", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/6467cda18c9f9b5f2f9a0aa1e2861c653e41f382", "tags": [ "x_transferred" ] } ] } ] } }