{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-53300", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.397Z", "datePublished": "2026-06-26T19:40:57.186Z", "dateUpdated": "2026-08-05T12:34:58.086Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:34:58.086Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: enetc: fix NTMP DMA use-after-free issue\n\nThe AI-generated review reported a potential DMA use-after-free issue\n[1]. If netc_xmit_ntmp_cmd() times out and returns an error, the pending\ncommand is not explicitly aborted, while ntmp_free_data_mem()\nunconditionally frees the DMA buffer. If the buffer has already been\nreallocated elsewhere, this may lead to silent memory corruption. Because\nthe hardware eventually processes the pending command and perform a DMA\nwrite of the response to the physical address of the freed buffer.\n\nTo resolve this issue, this patch does the following modifications:\n\n1. Convert cbdr->ring_lock from a spinlock to a mutex\n\nThe lock was originally a spinlock in case NTMP operations might be\ninvoked from atomic context. After downstream support for all NTMP\ntables, no such usage has materialized. A mutex lock is now required\nbecause the driver now needs to reclaim used BDs and release associated\nDMA memory within the lock's context, while dma_free_coherent() might\nsleep.\n\n2. Introduce software command BD (struct netc_swcbd)\n\nThe hardware write-back overwrites the addr and len fields of the BD,\nso the driver cannot rely on the hardware BD to free the associated DMA\nmemory. The driver now maintains a software shadow BD storing the DMA\nbuffer pointer, DMA address, and size. And netc_xmit_ntmp_cmd() only\nreclaims older BDs when the number of used BDs reaches\nNETC_CBDR_CLEAN_WORK (16). The software BD enables correct DMA memory\nrelease. With this, struct ntmp_dma_buf and ntmp_free_data_mem() are no\nlonger needed and are removed.\n\n3. Require callers to hold ring_lock across netc_xmit_ntmp_cmd()\n\nnetc_xmit_ntmp_cmd() releases the ring_lock before the caller finishes\nconsuming the response. At this point, if a concurrent thread submits\na new command, it may trigger ntmp_clean_cbdr() and free the DMA buffer\nwhile it is still in use. Move ring_lock ownership to the caller to\nensure the response buffer cannot be reclaimed prematurely. So the\nhelpers ntmp_select_and_lock_cbdr() and ntmp_unlock_cbdr() are added.\n\nThese changes eliminate the DMA use-after-free condition and ensure safe\nand consistent BD reclamation and DMA buffer lifecycle management." } ], "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 NTMP command path is reached through local ethtool ioctl/netlink RSS operations and driver/debugfs paths, not by processing remote network packets. A local process on a system with the affected ENETC4 device can invoke the relevant get-RSS path.\nAC:L - The attacker can repeatedly drive NTMP commands through ordinary ethtool RSS queries/updates and does not need to win a race against another principal. Because this is a DMA use-after-free and uncertainty is scored toward severity, the complexity is low.\nPR:L - The ethtool RSS get path is explicitly allowed to unprivileged local users and reaches `ntmp_rsst_query_entry`; set paths require CAP_NET_ADMIN but are not needed. This requires basic local execution, so it is PR:L under the provided rubric.\nUI:N - No victim action is required once the attacker has local execution. The attacker directly invokes the ioctl/netlink operation.\nS:U - The corruption affects kernel/driver-managed host memory within the same security authority. This is not a VM escape or separate IOMMU protection-domain bypass.\nC:H - The bug is a DMA use-after-free: after timeout the hardware may write a response to memory that has been freed and reallocated. Such kernel memory corruption is treated as capable of enabling information disclosure.\nI:H - The stale DMA write can corrupt reallocated kernel memory, potentially altering kernel data structures or enabling code execution. Per the UAF guidance, integrity impact is high.\nA:H - The same freed-memory DMA write can cause kernel memory corruption, oops, panic, or device/driver instability. Repeated triggering can therefore produce high availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/freescale/enetc/ntmp.c", "drivers/net/ethernet/freescale/enetc/ntmp_private.h", "include/linux/fsl/ntmp.h" ], "versions": [ { "version": "4701073c3debd16d7f534f3eb808bd9b50601c0c", "lessThan": "37c8933064be714ee672b0a0523c2fd045b73b3d", "status": "affected", "versionType": "git" }, { "version": "4701073c3debd16d7f534f3eb808bd9b50601c0c", "lessThan": "655d9ce9b1d3db0aa5271acb5e5101c66bd0d58b", "status": "affected", "versionType": "git" }, { "version": "4701073c3debd16d7f534f3eb808bd9b50601c0c", "lessThan": "3cade698881eb238f88cbbfec82acc2110440a3f", "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/net/ethernet/freescale/enetc/ntmp.c", "drivers/net/ethernet/freescale/enetc/ntmp_private.h", "include/linux/fsl/ntmp.h" ], "versions": [ { "version": "6.16", "status": "affected" }, { "version": "0", "lessThan": "6.16", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.33", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.10", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "6.16", "versionEndExcluding": "6.18.33" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.0.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/37c8933064be714ee672b0a0523c2fd045b73b3d" }, { "url": "https://git.kernel.org/stable/c/655d9ce9b1d3db0aa5271acb5e5101c66bd0d58b" }, { "url": "https://git.kernel.org/stable/c/3cade698881eb238f88cbbfec82acc2110440a3f" } ], "title": "net: enetc: fix NTMP DMA use-after-free issue", "x_generator": { "engine": "bippy-1.2.0" } } } }