{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74545", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.914Z", "datePublished": "2026-08-15T12:27:54.536Z", "dateUpdated": "2026-08-17T05:48:32.121Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:48:32.121Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrtase: fix double free of multi-frag skb on DMA map failure\n\nIn rtase_start_xmit(), when the head buffer DMA mapping fails after\nrtase_xmit_frags() has mapped all fragments, the error path clears\nthe fragment descriptors with rtase_tx_clear_range(), which frees\nthe skb through the last-frag slot and accounts tx_dropped. Control\nthen falls through to the common error label, which frees the same\nskb a second time and counts it again.\n\nReturn right after clearing the fragments when the skb owns frags;\nthe no-frag case still drops through and frees the head skb once." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The flaw is in rtase_start_xmit (ndo_start_xmit) on the Realtek Automotive Switch PCIe netdev; a remote peer can reach it by sending traffic that the host forwards, bridges, or answers out the rtase interface on automotive gateways and industrial routers without local shell access.\nAC:L - NETIF_F_SG enables multi-fragment TX skbs that rtase_xmit_frags maps before the head; an attacker can reliably create such packets and pressure SWIOTLB/IOVA resources with concurrent egress so the final head dma_map_single fails after fragment mapping succeeds, deterministically hitting the buggy error path.\nPR:N - Exploitation needs only the ability to inject or induce network traffic transmitted via the rtase netdev; no target credentials, capabilities, or local account are required on forwarding automotive/industrial gateways where this driver is deployed.\nUI:N - No victim interaction is required; the double free occurs automatically when the kernel queues a multi-fragment skb and the head DMA mapping fails during normal transmit error handling.\nS:U - The double free corrupts kernel heap allocator state on the host running the rtase driver; it does not cross VM, container, or IOMMU security boundaries.\nC:H - Double-freeing the same skb is kernel heap memory corruption that can corrupt freelist metadata and enable reuse of freed skb memory for arbitrary kernel memory disclosure, not merely a bounded leak.\nI:H - Heap corruption from freeing the same skb twice can be shaped into arbitrary kernel memory writes or control-flow hijacking via slab reuse, not limited to dropping a single packet.\nA:H - Double-freeing an skb reliably corrupts the slab allocator and can trigger immediate oops, panic, or watchdog reset; the attacker can repeat multi-fragment transmits under DMA pressure for sustained denial of service on safety-critical automotive networks." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/realtek/rtase/rtase_main.c" ], "versions": [ { "version": "d6e882b89fdf80be0ab4f914ec10f75215e49495", "lessThan": "4f09172aff5f73a5e914f4fbc0d00a1c2ea9f7cb", "status": "affected", "versionType": "git" }, { "version": "d6e882b89fdf80be0ab4f914ec10f75215e49495", "lessThan": "db986098f30881fafcc752800aa3b13fd289c922", "status": "affected", "versionType": "git" }, { "version": "d6e882b89fdf80be0ab4f914ec10f75215e49495", "lessThan": "de691dc3227b061c4d0beba9f0128fe1ff33dd68", "status": "affected", "versionType": "git" }, { "version": "d6e882b89fdf80be0ab4f914ec10f75215e49495", "lessThan": "6fb7b769d6ed6d1d2e02af4a80e57a2477f35086", "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/realtek/rtase/rtase_main.c" ], "versions": [ { "version": "6.12", "status": "affected" }, { "version": "0", "lessThan": "6.12", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.103", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.44", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.8", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.12", "versionEndExcluding": "6.12.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.18.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "7.1.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4f09172aff5f73a5e914f4fbc0d00a1c2ea9f7cb" }, { "url": "https://git.kernel.org/stable/c/db986098f30881fafcc752800aa3b13fd289c922" }, { "url": "https://git.kernel.org/stable/c/de691dc3227b061c4d0beba9f0128fe1ff33dd68" }, { "url": "https://git.kernel.org/stable/c/6fb7b769d6ed6d1d2e02af4a80e57a2477f35086" } ], "title": "rtase: fix double free of multi-frag skb on DMA map failure", "x_generator": { "engine": "bippy-1.2.0" } } } }