{"api_version":"1","generated_at":"2026-04-17T06:02:46+00:00","cve":"CVE-2026-31411","urls":{"html":"https://cve.report/CVE-2026-31411","api":"https://cve.report/api/cve/CVE-2026-31411.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-31411","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-31411"},"summary":{"title":"net: atm: fix crash due to unvalidated vcc pointer in sigd_send()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: atm: fix crash due to unvalidated vcc pointer in sigd_send()\n\nReproducer available at [1].\n\nThe ATM send path (sendmsg -> vcc_sendmsg -> sigd_send) reads the vcc\npointer from msg->vcc and uses it directly without any validation. This\npointer comes from userspace via sendmsg() and can be arbitrarily forged:\n\n    int fd = socket(AF_ATMSVC, SOCK_DGRAM, 0);\n    ioctl(fd, ATMSIGD_CTRL);  // become ATM signaling daemon\n    struct msghdr msg = { .msg_iov = &iov, ... };\n    *(unsigned long *)(buf + 4) = 0xdeadbeef;  // fake vcc pointer\n    sendmsg(fd, &msg, 0);  // kernel dereferences 0xdeadbeef\n\nIn normal operation, the kernel sends the vcc pointer to the signaling\ndaemon via sigd_enq() when processing operations like connect(), bind(),\nor listen(). The daemon is expected to return the same pointer when\nresponding. However, a malicious daemon can send arbitrary pointer values.\n\nFix this by introducing find_get_vcc() which validates the pointer by\nsearching through vcc_hash (similar to how sigd_close() iterates over\nall VCCs), and acquires a reference via sock_hold() if found.\n\nSince struct atm_vcc embeds struct sock as its first member, they share\nthe same lifetime. Therefore using sock_hold/sock_put is sufficient to\nkeep the vcc alive while it is being used.\n\nNote that there may be a race with sigd_close() which could mark the vcc\nwith various flags (e.g., ATM_VF_RELEASED) after find_get_vcc() returns.\nHowever, sock_hold() guarantees the memory remains valid, so this race\nonly affects the logical state, not memory safety.\n\n[1]: https://gist.github.com/mrpre/1ba5949c45529c511152e2f4c755b0f3","state":"PUBLISHED","assigner":"Linux","published_at":"2026-04-08 14:16:27","updated_at":"2026-04-08 21:26:13"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/ae88a5d2f29b69819dc7b04086734439d074a643","name":"https://git.kernel.org/stable/c/ae88a5d2f29b69819dc7b04086734439d074a643","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/440c9a5fc477a8ee259d8bf669531250b8398651","name":"https://git.kernel.org/stable/c/440c9a5fc477a8ee259d8bf669531250b8398651","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3e1a8b00095246a9a2b46b57f6d471c6d3c00ed2","name":"https://git.kernel.org/stable/c/3e1a8b00095246a9a2b46b57f6d471c6d3c00ed2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1c8bda3df028d5e54134077dcd09f46ca8cfceb5","name":"https://git.kernel.org/stable/c/1c8bda3df028d5e54134077dcd09f46ca8cfceb5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e3f80666c2739296c3b69a127300455c43aa1067","name":"https://git.kernel.org/stable/c/e3f80666c2739296c3b69a127300455c43aa1067","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/69d3f9ee5489e6e8b66defcfa226e91d82393297","name":"https://git.kernel.org/stable/c/69d3f9ee5489e6e8b66defcfa226e91d82393297","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/21c303fec138c002f90ed33bce60e807d53072bb","name":"https://git.kernel.org/stable/c/21c303fec138c002f90ed33bce60e807d53072bb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c96549d07dfdd51aadf0722cfb40711574424840","name":"https://git.kernel.org/stable/c/c96549d07dfdd51aadf0722cfb40711574424840","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-31411","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31411","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 c96549d07dfdd51aadf0722cfb40711574424840 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 1c8bda3df028d5e54134077dcd09f46ca8cfceb5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 3e1a8b00095246a9a2b46b57f6d471c6d3c00ed2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 e3f80666c2739296c3b69a127300455c43aa1067 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.202 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.165 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.128 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.75 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.14 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.4 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"31411","cve":"CVE-2026-31411","epss":"0.000320000","percentile":"0.090950000","score_date":"2026-04-14","updated_at":"2026-04-15 00:18:08"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/atm/signaling.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"c96549d07dfdd51aadf0722cfb40711574424840","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"1c8bda3df028d5e54134077dcd09f46ca8cfceb5","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"3e1a8b00095246a9a2b46b57f6d471c6d3c00ed2","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"e3f80666c2739296c3b69a127300455c43aa1067","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"21c303fec138c002f90ed33bce60e807d53072bb","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"69d3f9ee5489e6e8b66defcfa226e91d82393297","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"440c9a5fc477a8ee259d8bf669531250b8398651","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"ae88a5d2f29b69819dc7b04086734439d074a643","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/atm/signaling.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":"5.10.252","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.202","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.165","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.128","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.75","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.14","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.252","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.202","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.165","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.128","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.75","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.14","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.4","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0-rc1","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: atm: fix crash due to unvalidated vcc pointer in sigd_send()\n\nReproducer available at [1].\n\nThe ATM send path (sendmsg -> vcc_sendmsg -> sigd_send) reads the vcc\npointer from msg->vcc and uses it directly without any validation. This\npointer comes from userspace via sendmsg() and can be arbitrarily forged:\n\n    int fd = socket(AF_ATMSVC, SOCK_DGRAM, 0);\n    ioctl(fd, ATMSIGD_CTRL);  // become ATM signaling daemon\n    struct msghdr msg = { .msg_iov = &iov, ... };\n    *(unsigned long *)(buf + 4) = 0xdeadbeef;  // fake vcc pointer\n    sendmsg(fd, &msg, 0);  // kernel dereferences 0xdeadbeef\n\nIn normal operation, the kernel sends the vcc pointer to the signaling\ndaemon via sigd_enq() when processing operations like connect(), bind(),\nor listen(). The daemon is expected to return the same pointer when\nresponding. However, a malicious daemon can send arbitrary pointer values.\n\nFix this by introducing find_get_vcc() which validates the pointer by\nsearching through vcc_hash (similar to how sigd_close() iterates over\nall VCCs), and acquires a reference via sock_hold() if found.\n\nSince struct atm_vcc embeds struct sock as its first member, they share\nthe same lifetime. Therefore using sock_hold/sock_put is sufficient to\nkeep the vcc alive while it is being used.\n\nNote that there may be a race with sigd_close() which could mark the vcc\nwith various flags (e.g., ATM_VF_RELEASED) after find_get_vcc() returns.\nHowever, sock_hold() guarantees the memory remains valid, so this race\nonly affects the logical state, not memory safety.\n\n[1]: https://gist.github.com/mrpre/1ba5949c45529c511152e2f4c755b0f3"}],"providerMetadata":{"dateUpdated":"2026-04-08T13:06:17.800Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/c96549d07dfdd51aadf0722cfb40711574424840"},{"url":"https://git.kernel.org/stable/c/1c8bda3df028d5e54134077dcd09f46ca8cfceb5"},{"url":"https://git.kernel.org/stable/c/3e1a8b00095246a9a2b46b57f6d471c6d3c00ed2"},{"url":"https://git.kernel.org/stable/c/e3f80666c2739296c3b69a127300455c43aa1067"},{"url":"https://git.kernel.org/stable/c/21c303fec138c002f90ed33bce60e807d53072bb"},{"url":"https://git.kernel.org/stable/c/69d3f9ee5489e6e8b66defcfa226e91d82393297"},{"url":"https://git.kernel.org/stable/c/440c9a5fc477a8ee259d8bf669531250b8398651"},{"url":"https://git.kernel.org/stable/c/ae88a5d2f29b69819dc7b04086734439d074a643"}],"title":"net: atm: fix crash due to unvalidated vcc pointer in sigd_send()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-31411","datePublished":"2026-04-08T13:06:17.800Z","dateReserved":"2026-03-09T15:48:24.087Z","dateUpdated":"2026-04-08T13:06:17.800Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-08 14:16:27","lastModifiedDate":"2026-04-08 21:26:13","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"31411","Ordinal":"1","Title":"net: atm: fix crash due to unvalidated vcc pointer in sigd_send(","CVE":"CVE-2026-31411","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"31411","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: atm: fix crash due to unvalidated vcc pointer in sigd_send()\n\nReproducer available at [1].\n\nThe ATM send path (sendmsg -> vcc_sendmsg -> sigd_send) reads the vcc\npointer from msg->vcc and uses it directly without any validation. This\npointer comes from userspace via sendmsg() and can be arbitrarily forged:\n\n    int fd = socket(AF_ATMSVC, SOCK_DGRAM, 0);\n    ioctl(fd, ATMSIGD_CTRL);  // become ATM signaling daemon\n    struct msghdr msg = { .msg_iov = &iov, ... };\n    *(unsigned long *)(buf + 4) = 0xdeadbeef;  // fake vcc pointer\n    sendmsg(fd, &msg, 0);  // kernel dereferences 0xdeadbeef\n\nIn normal operation, the kernel sends the vcc pointer to the signaling\ndaemon via sigd_enq() when processing operations like connect(), bind(),\nor listen(). The daemon is expected to return the same pointer when\nresponding. However, a malicious daemon can send arbitrary pointer values.\n\nFix this by introducing find_get_vcc() which validates the pointer by\nsearching through vcc_hash (similar to how sigd_close() iterates over\nall VCCs), and acquires a reference via sock_hold() if found.\n\nSince struct atm_vcc embeds struct sock as its first member, they share\nthe same lifetime. Therefore using sock_hold/sock_put is sufficient to\nkeep the vcc alive while it is being used.\n\nNote that there may be a race with sigd_close() which could mark the vcc\nwith various flags (e.g., ATM_VF_RELEASED) after find_get_vcc() returns.\nHowever, sock_hold() guarantees the memory remains valid, so this race\nonly affects the logical state, not memory safety.\n\n[1]: https://gist.github.com/mrpre/1ba5949c45529c511152e2f4c755b0f3","Type":"Description","Title":"net: atm: fix crash due to unvalidated vcc pointer in sigd_send("}]}}}