{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-99055", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.388Z", "datePublished": "2026-10-23T12:22:39.451Z", "dateUpdated": "2026-10-23T12:22:39.451Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-23T12:22:39.451Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: reject net_iov in zerocopy receive mapping hints\n\nAfter copying a readable prefix, receive_fallback_to_copy() asks\ntcp_zerocopy_set_hint_for_skb() where page mapping can resume. If the\nnext skb is unreadable, find_next_mappable_frag() passes its net_iov\nfragment to can_map_frag().\n\nskb_frag_page() returns NULL for a net_iov, but can_map_frag()\ndereferences it in PageCompound(). A v7.2 KASAN run on a connected TCP\nsocket with 64 readable bytes followed by a 4096-byte NET_IOV_DMABUF\nfragment reported:\n\n BUG: KASAN: null-ptr-deref in can_map_frag\n tcp_zerocopy_receive -> can_map_frag\n Kernel panic - not syncing: KASAN: panic_on_warn set\n\nThe diagnostic inserted the net_iov directly because the test host has\nno devmem-capable NIC. Hardware end-to-end reachability remains untested\nand requires CONFIG_NET_DEVMEM plus a supported DMA-buf-bound RX queue.\n\nReject all net_iov fragments before skb_frag_page(). This covers both\nDMABUF and IOURING net_iov types while leaving page-backed checks\nunchanged. With the guard, the same queue copied the readable prefix,\nreturned a 4096-byte skip hint, and completed without a fault."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/ipv4/tcp.c"], "versions": [{"version": "9f6b619edf2e85746f261b42ae8f818a59d126f7", "lessThan": "563d3564513496b9ce3b3ba7a5154427554d0f06", "status": "affected", "versionType": "git"}, {"version": "9f6b619edf2e85746f261b42ae8f818a59d126f7", "lessThan": "1c7463ac0e99cc91c4eecc1b69a740ef1a619932", "status": "affected", "versionType": "git"}, {"version": "9f6b619edf2e85746f261b42ae8f818a59d126f7", "lessThan": "3aa6f536a95eb0617c313ae2eb76fdfa85331f85", "status": "affected", "versionType": "git"}, {"version": "9f6b619edf2e85746f261b42ae8f818a59d126f7", "lessThan": "8b1f0af1fd5fd113432233ed8a3862ee7c30a84f", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/ipv4/tcp.c"], "versions": [{"version": "6.12", "status": "affected"}, {"version": "0", "lessThan": "6.12", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.113", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.57", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.11", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "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": "6.12.113"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.18.57"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "7.2.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/563d3564513496b9ce3b3ba7a5154427554d0f06"}, {"url": "https://git.kernel.org/stable/c/1c7463ac0e99cc91c4eecc1b69a740ef1a619932"}, {"url": "https://git.kernel.org/stable/c/3aa6f536a95eb0617c313ae2eb76fdfa85331f85"}, {"url": "https://git.kernel.org/stable/c/8b1f0af1fd5fd113432233ed8a3862ee7c30a84f"}], "title": "tcp: reject net_iov in zerocopy receive mapping hints", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/ipv4/tcp.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "563d3564513496b9ce3b3ba7a5154427554d0f06", "status": "affected", "version": "9f6b619edf2e85746f261b42ae8f818a59d126f7", "versionType": "git"}, {"lessThan": "1c7463ac0e99cc91c4eecc1b69a740ef1a619932", "status": "affected", "version": "9f6b619edf2e85746f261b42ae8f818a59d126f7", "versionType": "git"}, {"lessThan": "3aa6f536a95eb0617c313ae2eb76fdfa85331f85", "status": "affected", "version": "9f6b619edf2e85746f261b42ae8f818a59d126f7", "versionType": "git"}, {"lessThan": "8b1f0af1fd5fd113432233ed8a3862ee7c30a84f", "status": "affected", "version": "9f6b619edf2e85746f261b42ae8f818a59d126f7", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/ipv4/tcp.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.12"}, {"lessThan": "6.12", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.113", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.57", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.11", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: reject net_iov in zerocopy receive mapping hints\n\nAfter copying a readable prefix, receive_fallback_to_copy() asks\ntcp_zerocopy_set_hint_for_skb() where page mapping can resume. If the\nnext skb is unreadable, find_next_mappable_frag() passes its net_iov\nfragment to can_map_frag().\n\nskb_frag_page() returns NULL for a net_iov, but can_map_frag()\ndereferences it in PageCompound(). A v7.2 KASAN run on a connected TCP\nsocket with 64 readable bytes followed by a 4096-byte NET_IOV_DMABUF\nfragment reported:\n\n BUG: KASAN: null-ptr-deref in can_map_frag\n tcp_zerocopy_receive -> can_map_frag\n Kernel panic - not syncing: KASAN: panic_on_warn set\n\nThe diagnostic inserted the net_iov directly because the test host has\nno devmem-capable NIC. Hardware end-to-end reachability remains untested\nand requires CONFIG_NET_DEVMEM plus a supported DMA-buf-bound RX queue.\n\nReject all net_iov fragments before skb_frag_page(). This covers both\nDMABUF and IOURING net_iov types while leaving page-backed checks\nunchanged. With the guard, the same queue copied the readable prefix,\nreturned a 4096-byte skip hint, and completed without a fault."}], "id": "CVE-2026-99055", "lastModified": "2026-10-23T13:17:29.140", "metrics": {}, "published": "2026-10-23T13:17:29.140", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1c7463ac0e99cc91c4eecc1b69a740ef1a619932"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3aa6f536a95eb0617c313ae2eb76fdfa85331f85"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/563d3564513496b9ce3b3ba7a5154427554d0f06"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8b1f0af1fd5fd113432233ed8a3862ee7c30a84f"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: tcp: reject net_iov in zerocopy receive mapping hints", "id": "2559801", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2559801"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.9", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-476", "details": ["In the Linux kernel, the following vulnerability has been resolved:\ntcp: reject net_iov in zerocopy receive mapping hints\nAfter copying a readable prefix, receive_fallback_to_copy() asks\ntcp_zerocopy_set_hint_for_skb() where page mapping can resume. If the\nnext skb is unreadable, find_next_mappable_frag() passes its net_iov\nfragment to can_map_frag().\nskb_frag_page() returns NULL for a net_iov, but can_map_frag()\ndereferences it in PageCompound(). A v7.2 KASAN run on a connected TCP\nsocket with 64 readable bytes followed by a 4096-byte NET_IOV_DMABUF\nfragment reported:\nBUG: KASAN: null-ptr-deref in can_map_frag\ntcp_zerocopy_receive -> can_map_frag\nKernel panic - not syncing: KASAN: panic_on_warn set\nThe diagnostic inserted the net_iov directly because the test host has\nno devmem-capable NIC. Hardware end-to-end reachability remains untested\nand requires CONFIG_NET_DEVMEM plus a supported DMA-buf-bound RX queue.\nReject all net_iov fragments before skb_frag_page(). This covers both\nDMABUF and IOURING net_iov types while leaving page-backed checks\nunchanged. With the guard, the same queue copied the readable prefix,\nreturned a 4096-byte skip hint, and completed without a fault.", "A flaw was found in the Linux kernel's TCP networking subsystem. When handling zero-copy data reception involving certain device memory buffers, the kernel fails to properly validate memory fragment types before dereferencing them, resulting in a null pointer dereference. An attacker sending traffic to an affected system can trigger this condition, causing a kernel crash and leading to a denial of service (DoS)."], "name": "CVE-2026-99055", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-10-23T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-99055\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-99055\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-99055.mbox"], "threat_severity": "Moderate"}