{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-23255", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:45.990Z", "datePublished": "2026-03-18T17:41:01.445Z", "dateUpdated": "2026-05-11T22:03:19.405Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T22:03:19.405Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: add proper RCU protection to /proc/net/ptype\n\nYin Fengwei reported an RCU stall in ptype_seq_show() and provided\na patch.\n\nReal issue is that ptype_seq_next() and ptype_seq_show() violate\nRCU rules.\n\nptype_seq_show() runs under rcu_read_lock(), and reads pt->dev\nto get device name without any barrier.\n\nAt the same time, concurrent writers can remove a packet_type structure\n(which is correctly freed after an RCU grace period) and clear pt->dev\nwithout an RCU grace period.\n\nDefine ptype_iter_state to carry a dev pointer along seq_net_private:\n\nstruct ptype_iter_state {\n\tstruct seq_net_private\tp;\n\tstruct net_device\t*dev; // added in this patch\n};\n\nWe need to record the device pointer in ptype_get_idx() and\nptype_seq_next() so that ptype_seq_show() is safe against\nconcurrent pt->dev changes.\n\nWe also need to add full RCU protection in ptype_seq_next().\n(Missing READ_ONCE() when reading list.next values)\n\nMany thanks to Dong Chenchen for providing a repro."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/core/net-procfs.c"], "versions": [{"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "002a73470b56848e4c81efeaaedd471e92d66d8d", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "dcefd3f0b9ed8288654c75254bdcee8e1085e861", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "589a530ae44d0c80f523fcfd1a15af8087f27d35", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "f613e8b4afea0cd17c7168e8b00e25bc8d33175d", "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/core/net-procfs.c"], "versions": [{"version": "2.6.12", "status": "affected"}, {"version": "0", "lessThan": "2.6.12", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.136", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.80", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.10", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19", "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": "2.6.12", "versionEndExcluding": "6.6.136"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.12.80"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.18.10"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.19"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/002a73470b56848e4c81efeaaedd471e92d66d8d"}, {"url": "https://git.kernel.org/stable/c/dcefd3f0b9ed8288654c75254bdcee8e1085e861"}, {"url": "https://git.kernel.org/stable/c/589a530ae44d0c80f523fcfd1a15af8087f27d35"}, {"url": "https://git.kernel.org/stable/c/f613e8b4afea0cd17c7168e8b00e25bc8d33175d"}], "title": "net: add proper RCU protection to /proc/net/ptype", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: add proper RCU protection to /proc/net/ptype\n\nYin Fengwei reported an RCU stall in ptype_seq_show() and provided\na patch.\n\nReal issue is that ptype_seq_next() and ptype_seq_show() violate\nRCU rules.\n\nptype_seq_show() runs under rcu_read_lock(), and reads pt->dev\nto get device name without any barrier.\n\nAt the same time, concurrent writers can remove a packet_type structure\n(which is correctly freed after an RCU grace period) and clear pt->dev\nwithout an RCU grace period.\n\nDefine ptype_iter_state to carry a dev pointer along seq_net_private:\n\nstruct ptype_iter_state {\n\tstruct seq_net_private\tp;\n\tstruct net_device\t*dev; // added in this patch\n};\n\nWe need to record the device pointer in ptype_get_idx() and\nptype_seq_next() so that ptype_seq_show() is safe against\nconcurrent pt->dev changes.\n\nWe also need to add full RCU protection in ptype_seq_next().\n(Missing READ_ONCE() when reading list.next values)\n\nMany thanks to Dong Chenchen for providing a repro."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet: a\u00f1adir protecci\u00f3n RCU adecuada a /proc/net/ptype\n\nYin Fengwei inform\u00f3 de un bloqueo RCU en ptype_seq_show() y proporcion\u00f3 un parche.\n\nEl problema real es que ptype_seq_next() y ptype_seq_show() violan las reglas RCU.\n\nptype_seq_show() se ejecuta bajo rcu_read_lock(), y lee pt->dev para obtener el nombre del dispositivo sin ninguna barrera.\n\nAl mismo tiempo, los escritores concurrentes pueden eliminar una estructura packet_type (que se libera correctamente despu\u00e9s de un per\u00edodo de gracia RCU) y borrar pt->dev sin un per\u00edodo de gracia RCU.\n\nDefinir ptype_iter_state para llevar un puntero dev junto con seq_net_private:\n\nstruct ptype_iter_state {\n\tstruct seq_net_private\tp;\n\tstruct net_device\t*dev; // a\u00f1adido en este parche\n};\n\nNecesitamos registrar el puntero del dispositivo en ptype_get_idx() y ptype_seq_next() para que ptype_seq_show() est\u00e9 a salvo de cambios concurrentes en pt->dev.\n\nTambi\u00e9n necesitamos a\u00f1adir protecci\u00f3n RCU completa en ptype_seq_next().\n(Falta READ_ONCE() al leer los valores de list.next)\n\nMuchas gracias a Dong Chenchen por proporcionar una reproducci\u00f3n."}], "id": "CVE-2026-23255", "lastModified": "2026-04-27T14:16:29.743", "metrics": {}, "published": "2026-03-18T18:16:23.687", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/002a73470b56848e4c81efeaaedd471e92d66d8d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/589a530ae44d0c80f523fcfd1a15af8087f27d35"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/dcefd3f0b9ed8288654c75254bdcee8e1085e861"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f613e8b4afea0cd17c7168e8b00e25bc8d33175d"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: net: add proper RCU protection to /proc/net/ptype", "id": "2448703", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2448703"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "details": ["No description is available for this CVE."], "name": "CVE-2026-23255", "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": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-03-18T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-23255\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-23255\nhttps://lore.kernel.org/linux-cve-announce/2026031817-CVE-2026-23255-fc51@gregkh/T"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,589a530ae44d0c80f523fcfd1a15af8087f27d35)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,f613e8b4afea0cd17c7168e8b00e25bc8d33175d)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "2.6.12"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,2.6.12)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.10,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.19,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "analysis": {"en": {"generated_at": "2026-03-27T11:51:29.800553+00:00", "value": {"mitigation_remediation": ["Apply a kernel update that includes the RCU protection patch, typically released in the latest stable kernel series.", "Verify the patch by checking the commit log for the changes to ptype_seq_show() and ptype_seq_next().", "If an immediate kernel upgrade is not possible, restrict access to /proc/net/ptype and limit the use of packet_type configurations to trusted administrators.", "Monitor system logs for signs of kernel stalling or repeated RCU warnings and apply the patch as soon as a suitable update becomes available."], "summary": {"action": "Immediate Patch", "impact": "Potential kernel freeze or crash due to improper RCU handling"}, "threat_synthesis": {"affected_systems": "All Linux kernel builds that do not contain the patch that adds proper RCU protection to /proc/net/ptype are affected. That includes all kernels before the commit that introduced the ptype_iter_state struct and the READ_ONCE() safeguards. The issue touches the core networking subsystem, so any system running an unpatched kernel is potentially vulnerable.", "description_and_impact": "The vulnerability is caused by a violation of RCU (Read\u2011Copy\u2011Update) rules in the Linux kernel\u2019s handling of /proc/net/ptype. The routine ptype_seq_show() obtains a device pointer while holding rcu_read_lock() without a memory barrier, and concurrent writers can delete the packet_type structure and clear its device pointer without waiting for an RCU grace period. This race can lead to a kernel stall or crash because the reader may access freed or invalid data, compromising system availability.", "risk_and_exploitability": "The CVSS score of 7.0 indicates moderate severity. The EPSS score is below 1\u202f% and the vulnerability is not listed in the CISA KEV catalog, suggesting limited exploitation in the wild. An attacker would need to induce a race condition against the packet_type list, which typically requires local or privileged access to manipulate /proc/net/ptype or to load drivers that modify packet_type entries. The most likely attack vector is a local privilege escalation or a malicious kernel module that performs concurrent modifications, though a remote attacker might trigger it through network traffic that causes concurrent writes if such an interface is exposed."}}}}, "created": "2026-03-19T08:56:11.571368+00:00", "updated": "2026-03-27T15:48:23.460452+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-366", "CWE-416"]}