{"api_version":"1","generated_at":"2026-04-26T06:37:11+00:00","cve":"CVE-2026-23286","urls":{"html":"https://cve.report/CVE-2026-23286","api":"https://cve.report/api/cve/CVE-2026-23286.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-23286","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-23286"},"summary":{"title":"atm: lec: fix null-ptr-deref in lec_arp_clear_vccs","description":"In the Linux kernel, the following vulnerability has been resolved:\n\natm: lec: fix null-ptr-deref in lec_arp_clear_vccs\n\nsyzkaller reported a null-ptr-deref in lec_arp_clear_vccs().\nThis issue can be easily reproduced using the syzkaller reproducer.\n\nIn the ATM LANE (LAN Emulation) module, the same atm_vcc can be shared by\nmultiple lec_arp_table entries (e.g., via entry->vcc or entry->recv_vcc).\nWhen the underlying VCC is closed, lec_vcc_close() iterates over all\nARP entries and calls lec_arp_clear_vccs() for each matched entry.\n\nFor example, when lec_vcc_close() iterates through the hlists in\npriv->lec_arp_empty_ones or other ARP tables:\n\n1. In the first iteration, for the first matched ARP entry sharing the VCC,\nlec_arp_clear_vccs() frees the associated vpriv (which is vcc->user_back)\nand sets vcc->user_back to NULL.\n2. In the second iteration, for the next matched ARP entry sharing the same\nVCC, lec_arp_clear_vccs() is called again. It obtains a NULL vpriv from\nvcc->user_back (via LEC_VCC_PRIV(vcc)) and then attempts to dereference it\nvia `vcc->pop = vpriv->old_pop`, leading to a null-ptr-deref crash.\n\nFix this by adding a null check for vpriv before dereferencing\nit. If vpriv is already NULL, it means the VCC has been cleared\nby a previous call, so we can safely skip the cleanup and just\nclear the entry's vcc/recv_vcc pointers.\n\nThe entire cleanup block (including vcc_release_async()) is placed inside\nthe vpriv guard because a NULL vpriv indicates the VCC has already been\nfully released by a prior iteration — repeating the teardown would\nredundantly set flags and trigger callbacks on an already-closing socket.\n\nThe Fixes tag points to the initial commit because the entry->vcc path has\nbeen vulnerable since the original code. The entry->recv_vcc path was later\nadded by commit 8d9f73c0ad2f (\"atm: fix a memory leak of vcc->user_back\")\nwith the same pattern, and both paths are fixed here.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-03-25 11:16:23","updated_at":"2026-04-18 09:16:16"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/7ea92ab075d809ec8a96669a5ecf00f752057875","name":"https://git.kernel.org/stable/c/7ea92ab075d809ec8a96669a5ecf00f752057875","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5f1cfea7921f5c126a441d973690eeba52677b64","name":"https://git.kernel.org/stable/c/5f1cfea7921f5c126a441d973690eeba52677b64","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8aff65a82b6389ec674d46e5b3d3ae6f07db5e3e","name":"https://git.kernel.org/stable/c/8aff65a82b6389ec674d46e5b3d3ae6f07db5e3e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/622062f24644b4536d3f437e0cf7a8c4bb421665","name":"https://git.kernel.org/stable/c/622062f24644b4536d3f437e0cf7a8c4bb421665","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e9665986eb127290ceb535bd5d04d7a84265d94f","name":"https://git.kernel.org/stable/c/e9665986eb127290ceb535bd5d04d7a84265d94f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2d9f57ea29a1f1772373b98a509b44d49fda609e","name":"https://git.kernel.org/stable/c/2d9f57ea29a1f1772373b98a509b44d49fda609e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/101bacb303e89dc2e0640ae6a5e0fb97c4eb45bb","name":"https://git.kernel.org/stable/c/101bacb303e89dc2e0640ae6a5e0fb97c4eb45bb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/30c9744a989feb22cfbb84170eb0e038a7a2c1da","name":"https://git.kernel.org/stable/c/30c9744a989feb22cfbb84170eb0e038a7a2c1da","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-23286","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23286","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 8aff65a82b6389ec674d46e5b3d3ae6f07db5e3e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 30c9744a989feb22cfbb84170eb0e038a7a2c1da git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 e9665986eb127290ceb535bd5d04d7a84265d94f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 622062f24644b4536d3f437e0cf7a8c4bb421665 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 2d9f57ea29a1f1772373b98a509b44d49fda609e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 7ea92ab075d809ec8a96669a5ecf00f752057875 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 5f1cfea7921f5c126a441d973690eeba52677b64 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 101bacb303e89dc2e0640ae6a5e0fb97c4eb45bb 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 5.10.253 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.203 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.167 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.130 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.77 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.17 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.7 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"23286","cve":"CVE-2026-23286","epss":"0.000320000","percentile":"0.092520000","score_date":"2026-04-21","updated_at":"2026-04-22 00:07:40"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/atm/lec.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"8aff65a82b6389ec674d46e5b3d3ae6f07db5e3e","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"30c9744a989feb22cfbb84170eb0e038a7a2c1da","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"e9665986eb127290ceb535bd5d04d7a84265d94f","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"622062f24644b4536d3f437e0cf7a8c4bb421665","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"2d9f57ea29a1f1772373b98a509b44d49fda609e","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"7ea92ab075d809ec8a96669a5ecf00f752057875","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"5f1cfea7921f5c126a441d973690eeba52677b64","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"101bacb303e89dc2e0640ae6a5e0fb97c4eb45bb","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/atm/lec.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":"5.10.*","status":"unaffected","version":"5.10.253","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.203","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.167","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.130","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.77","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.17","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.7","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.253","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.203","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.167","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.130","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.77","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.17","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.7","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","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\natm: lec: fix null-ptr-deref in lec_arp_clear_vccs\n\nsyzkaller reported a null-ptr-deref in lec_arp_clear_vccs().\nThis issue can be easily reproduced using the syzkaller reproducer.\n\nIn the ATM LANE (LAN Emulation) module, the same atm_vcc can be shared by\nmultiple lec_arp_table entries (e.g., via entry->vcc or entry->recv_vcc).\nWhen the underlying VCC is closed, lec_vcc_close() iterates over all\nARP entries and calls lec_arp_clear_vccs() for each matched entry.\n\nFor example, when lec_vcc_close() iterates through the hlists in\npriv->lec_arp_empty_ones or other ARP tables:\n\n1. In the first iteration, for the first matched ARP entry sharing the VCC,\nlec_arp_clear_vccs() frees the associated vpriv (which is vcc->user_back)\nand sets vcc->user_back to NULL.\n2. In the second iteration, for the next matched ARP entry sharing the same\nVCC, lec_arp_clear_vccs() is called again. It obtains a NULL vpriv from\nvcc->user_back (via LEC_VCC_PRIV(vcc)) and then attempts to dereference it\nvia `vcc->pop = vpriv->old_pop`, leading to a null-ptr-deref crash.\n\nFix this by adding a null check for vpriv before dereferencing\nit. If vpriv is already NULL, it means the VCC has been cleared\nby a previous call, so we can safely skip the cleanup and just\nclear the entry's vcc/recv_vcc pointers.\n\nThe entire cleanup block (including vcc_release_async()) is placed inside\nthe vpriv guard because a NULL vpriv indicates the VCC has already been\nfully released by a prior iteration — repeating the teardown would\nredundantly set flags and trigger callbacks on an already-closing socket.\n\nThe Fixes tag points to the initial commit because the entry->vcc path has\nbeen vulnerable since the original code. The entry->recv_vcc path was later\nadded by commit 8d9f73c0ad2f (\"atm: fix a memory leak of vcc->user_back\")\nwith the same pattern, and both paths are fixed here."}],"providerMetadata":{"dateUpdated":"2026-04-18T08:57:38.115Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/8aff65a82b6389ec674d46e5b3d3ae6f07db5e3e"},{"url":"https://git.kernel.org/stable/c/30c9744a989feb22cfbb84170eb0e038a7a2c1da"},{"url":"https://git.kernel.org/stable/c/e9665986eb127290ceb535bd5d04d7a84265d94f"},{"url":"https://git.kernel.org/stable/c/622062f24644b4536d3f437e0cf7a8c4bb421665"},{"url":"https://git.kernel.org/stable/c/2d9f57ea29a1f1772373b98a509b44d49fda609e"},{"url":"https://git.kernel.org/stable/c/7ea92ab075d809ec8a96669a5ecf00f752057875"},{"url":"https://git.kernel.org/stable/c/5f1cfea7921f5c126a441d973690eeba52677b64"},{"url":"https://git.kernel.org/stable/c/101bacb303e89dc2e0640ae6a5e0fb97c4eb45bb"}],"title":"atm: lec: fix null-ptr-deref in lec_arp_clear_vccs","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-23286","datePublished":"2026-03-25T10:26:45.531Z","dateReserved":"2026-01-13T15:37:45.992Z","dateUpdated":"2026-04-18T08:57:38.115Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-03-25 11:16:23","lastModifiedDate":"2026-04-18 09:16:16","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"23286","Ordinal":"1","Title":"atm: lec: fix null-ptr-deref in lec_arp_clear_vccs","CVE":"CVE-2026-23286","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"23286","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\natm: lec: fix null-ptr-deref in lec_arp_clear_vccs\n\nsyzkaller reported a null-ptr-deref in lec_arp_clear_vccs().\nThis issue can be easily reproduced using the syzkaller reproducer.\n\nIn the ATM LANE (LAN Emulation) module, the same atm_vcc can be shared by\nmultiple lec_arp_table entries (e.g., via entry->vcc or entry->recv_vcc).\nWhen the underlying VCC is closed, lec_vcc_close() iterates over all\nARP entries and calls lec_arp_clear_vccs() for each matched entry.\n\nFor example, when lec_vcc_close() iterates through the hlists in\npriv->lec_arp_empty_ones or other ARP tables:\n\n1. In the first iteration, for the first matched ARP entry sharing the VCC,\nlec_arp_clear_vccs() frees the associated vpriv (which is vcc->user_back)\nand sets vcc->user_back to NULL.\n2. In the second iteration, for the next matched ARP entry sharing the same\nVCC, lec_arp_clear_vccs() is called again. It obtains a NULL vpriv from\nvcc->user_back (via LEC_VCC_PRIV(vcc)) and then attempts to dereference it\nvia `vcc->pop = vpriv->old_pop`, leading to a null-ptr-deref crash.\n\nFix this by adding a null check for vpriv before dereferencing\nit. If vpriv is already NULL, it means the VCC has been cleared\nby a previous call, so we can safely skip the cleanup and just\nclear the entry's vcc/recv_vcc pointers.\n\nThe entire cleanup block (including vcc_release_async()) is placed inside\nthe vpriv guard because a NULL vpriv indicates the VCC has already been\nfully released by a prior iteration — repeating the teardown would\nredundantly set flags and trigger callbacks on an already-closing socket.\n\nThe Fixes tag points to the initial commit because the entry->vcc path has\nbeen vulnerable since the original code. The entry->recv_vcc path was later\nadded by commit 8d9f73c0ad2f (\"atm: fix a memory leak of vcc->user_back\")\nwith the same pattern, and both paths are fixed here.","Type":"Description","Title":"atm: lec: fix null-ptr-deref in lec_arp_clear_vccs"}]}}}