{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64055", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.030Z", "datePublished": "2026-07-19T15:39:37.077Z", "dateUpdated": "2026-08-05T12:38:44.658Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:38:44.658Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ethernet: cortina: Carry over frag counter\n\nThe gmac_rx() NAPI poll function assembles packets in an\nSKB from a ring buffer.\n\nIf the ring buffer gets completely emptied during a poll cycle,\nwe exit gmac_rx(), but the packet is not yet completely\nassembled in the SKB, yet the fragment counter frag_nr is\nreset to zero on the next invocation.\n\nSolve this by making the RX fragment counter a part of the\nport struct, and carry it over between invocations.\n\nReset the fragment counter only right after calling\nnapi_gro_frags(), on error (after calling napi_free_frags())\nor if stopping the port.\n\nReset it in some place where not strictly necessary just to\nemphasize what is going on.\n\nThis was found by Sashiko during normal patch review." } ], "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 bug is in the Cortina Gemini GMAC RX NAPI path (gmac_rx), which processes incoming Ethernet frames delivered by hardware DMA; a remote attacker on any routable network can send crafted multi-fragment frames to the device's NIC without local access.\nAC:L - An attacker controls frame size (jumbo frames exceeding the 2048-byte RX buffer fragment size) and traffic timing to drain the RX ring mid-packet across NAPI poll cycles, reliably reproducing the lost frag_nr condition without depending on uncontrollable system state.\nPR:N - Exploitation requires only the ability to send Ethernet frames to the target interface; no local account, kernel capability, or authentication on the victim system is needed.\nUI:N - Packet reception and NAPI processing are fully automatic; no victim user action such as mounting a filesystem or opening a file is required.\nS:U - The vulnerability corrupts kernel skb metadata in the network driver and affects only the kernel's own security domain; it does not cross a VM, container, or IOMMU boundary by itself.\nC:H - Resetting frag_nr to zero while rx_skb retains prior fragments causes skb_fill_page_desc to overwrite fragment slot 0, shrinks nr_frags while inflating skb->len, and can trigger out-of-bounds kernel reads when GRO and the network stack process the corrupted skb.\nI:H - The bug corrupts kernel heap skb fragment metadata (overwritten page descriptors, inconsistent nr_frags versus len), which is memory corruption in kernel structures that can be leveraged for arbitrary write or control-flow hijack primitives.\nA:H - Submitting a corrupted multi-fragment skb to napi_gro_frags and the upper network stack can cause kernel oops, BUG, or panic during fragment traversal, checksum, or GRO processing." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/cortina/gemini.c" ], "versions": [ { "version": "4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88", "lessThan": "df31e3b64455293df1ea89c7da7d5c9bfbcdd253", "status": "affected", "versionType": "git" }, { "version": "4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88", "lessThan": "7af1fabdee744b7995fe01b30b77dfc397657cb5", "status": "affected", "versionType": "git" }, { "version": "4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88", "lessThan": "75105fcf73f1ce7d9f769aaefec6e6d6645d5ac0", "status": "affected", "versionType": "git" }, { "version": "4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88", "lessThan": "78cf08b3be47c28f07008a76c932bad7cdffa9d8", "status": "affected", "versionType": "git" }, { "version": "4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88", "lessThan": "7123cf481e21b54eb6adc4cb0d8dc2876aeaee41", "status": "affected", "versionType": "git" }, { "version": "4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88", "lessThan": "c373b34877afea61c89e0dd2e38948c624249b9b", "status": "affected", "versionType": "git" }, { "version": "4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88", "lessThan": "46806096f35b8d3dfa2f321ddd77f597edcdb85f", "status": "affected", "versionType": "git" }, { "version": "4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88", "lessThan": "ebd8ec2b309e3a447851b456ccaf8fb39f3661e7", "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/cortina/gemini.c" ], "versions": [ { "version": "4.16", "status": "affected" }, { "version": "0", "lessThan": "4.16", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.258", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.209", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.142", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.92", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.34", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.11", "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": "4.16", "versionEndExcluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.6.142" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.12.92" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.18.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "7.0.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/df31e3b64455293df1ea89c7da7d5c9bfbcdd253" }, { "url": "https://git.kernel.org/stable/c/7af1fabdee744b7995fe01b30b77dfc397657cb5" }, { "url": "https://git.kernel.org/stable/c/75105fcf73f1ce7d9f769aaefec6e6d6645d5ac0" }, { "url": "https://git.kernel.org/stable/c/78cf08b3be47c28f07008a76c932bad7cdffa9d8" }, { "url": "https://git.kernel.org/stable/c/7123cf481e21b54eb6adc4cb0d8dc2876aeaee41" }, { "url": "https://git.kernel.org/stable/c/c373b34877afea61c89e0dd2e38948c624249b9b" }, { "url": "https://git.kernel.org/stable/c/46806096f35b8d3dfa2f321ddd77f597edcdb85f" }, { "url": "https://git.kernel.org/stable/c/ebd8ec2b309e3a447851b456ccaf8fb39f3661e7" } ], "title": "net: ethernet: cortina: Carry over frag counter", "x_generator": { "engine": "bippy-1.2.0" } } } }