{"api_version":"1","generated_at":"2026-04-26T00:13:50+00:00","cve":"CVE-2026-23255","urls":{"html":"https://cve.report/CVE-2026-23255","api":"https://cve.report/api/cve/CVE-2026-23255.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-23255","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-23255"},"summary":{"title":"net: add proper RCU protection to /proc/net/ptype","description":"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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-03-18 18:16:23","updated_at":"2026-04-02 12:16:19"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/589a530ae44d0c80f523fcfd1a15af8087f27d35","name":"https://git.kernel.org/stable/c/589a530ae44d0c80f523fcfd1a15af8087f27d35","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f613e8b4afea0cd17c7168e8b00e25bc8d33175d","name":"https://git.kernel.org/stable/c/f613e8b4afea0cd17c7168e8b00e25bc8d33175d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/dcefd3f0b9ed8288654c75254bdcee8e1085e861","name":"https://git.kernel.org/stable/c/dcefd3f0b9ed8288654c75254bdcee8e1085e861","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-23255","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23255","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 dcefd3f0b9ed8288654c75254bdcee8e1085e861 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 589a530ae44d0c80f523fcfd1a15af8087f27d35 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 f613e8b4afea0cd17c7168e8b00e25bc8d33175d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2.6.12","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 2.6.12 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.80 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.10 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"23255","cve":"CVE-2026-23255","epss":"0.000220000","percentile":"0.058640000","score_date":"2026-04-07","updated_at":"2026-04-08 00:03:40"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/core/net-procfs.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"dcefd3f0b9ed8288654c75254bdcee8e1085e861","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"589a530ae44d0c80f523fcfd1a15af8087f27d35","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"f613e8b4afea0cd17c7168e8b00e25bc8d33175d","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/core/net-procfs.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.12"},{"lessThan":"2.6.12","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.80","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.10","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"6.19","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.80","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.10","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19","versionStartIncluding":"2.6.12","vulnerable":true}],"negate":false,"operator":"OR"}]}],"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."}],"providerMetadata":{"dateUpdated":"2026-04-02T11:30:54.294Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"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"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-23255","datePublished":"2026-03-18T17:41:01.445Z","dateReserved":"2026-01-13T15:37:45.990Z","dateUpdated":"2026-04-02T11:30:54.294Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-03-18 18:16:23","lastModifiedDate":"2026-04-02 12:16:19","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"23255","Ordinal":"1","Title":"net: add proper RCU protection to /proc/net/ptype","CVE":"CVE-2026-23255","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"23255","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"net: add proper RCU protection to /proc/net/ptype"}]}}}