{"id":"CVE-2026-46027","state":"PUBLISHED","title":"net/smc: avoid early lgr access in smc_clc_wait_msg","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: avoid early lgr access in smc_clc_wait_msg\n\nA CLC decline can be received while the handshake is still in an early\nstage, before the connection has been associated with a link group.\n\nThe decline handling in smc_clc_wait_msg() updates link-group level sync\nstate for first-contact declines, but that state only exists after link\ngroup setup has completed. Guard the link-group update accordingly and\nkeep the per-socket peer diagnosis handling unchanged.\n\nThis preserves the existing sync_err handling for established link-group\ncontexts and avoids touching link-group state before it is available.","publishedAt":"2026-05-27T12:56:35.628Z","updatedAt":"2026-10-19T19:26:41.717Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"257cdf0c5ced9c0fba8aba501d94b0a5fcef2086","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"22546729b96fc873b23065dc49e3d73c45cfb874","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"5eedbfd82c2884e0010fdfb3c9446a6ebcadb691","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"f0858e1d5624bb120b198f2a8528f97a9b0ae069","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"6180a296ca65b08a81914805cbc0f78da5f10a1f","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"ea0b5d0fe96356dce38f98375a57c52a04e13712","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"83bcf9228b0501694fb2589ed1d142855a2887f2","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"5a8db80f721deee8e916c2cfdee78decda02ce4f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/smc/smc_clc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.11","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.140","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.86","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.27","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.4","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/smc/smc_clc.c"]}],"references":["https://git.kernel.org/stable/c/257cdf0c5ced9c0fba8aba501d94b0a5fcef2086","https://git.kernel.org/stable/c/22546729b96fc873b23065dc49e3d73c45cfb874","https://git.kernel.org/stable/c/5eedbfd82c2884e0010fdfb3c9446a6ebcadb691","https://git.kernel.org/stable/c/f0858e1d5624bb120b198f2a8528f97a9b0ae069","https://git.kernel.org/stable/c/6180a296ca65b08a81914805cbc0f78da5f10a1f","https://git.kernel.org/stable/c/ea0b5d0fe96356dce38f98375a57c52a04e13712","https://git.kernel.org/stable/c/83bcf9228b0501694fb2589ed1d142855a2887f2","https://git.kernel.org/stable/c/5a8db80f721deee8e916c2cfdee78decda02ce4f"],"weaknesses":["CWE-617"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/46xxx/CVE-2026-46027.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46027","state":"PUBLISHED","datePublished":"2026-05-27T12:56:35.628Z","dateUpdated":"2026-10-19T19:26:41.717Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.093Z"},"containers":{"cna":{"title":"net/smc: avoid early lgr access in smc_clc_wait_msg","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: avoid early lgr access in smc_clc_wait_msg\n\nA CLC decline can be received while the handshake is still in an early\nstage, before the connection has been associated with a link group.\n\nThe decline handling in smc_clc_wait_msg() updates link-group level sync\nstate for first-contact declines, but that state only exists after link\ngroup setup has completed. Guard the link-group update accordingly and\nkeep the per-socket peer diagnosis handling unchanged.\n\nThis preserves the existing sync_err handling for established link-group\ncontexts and avoids touching link-group state before it is available."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"257cdf0c5ced9c0fba8aba501d94b0a5fcef2086","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"22546729b96fc873b23065dc49e3d73c45cfb874","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"5eedbfd82c2884e0010fdfb3c9446a6ebcadb691","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"f0858e1d5624bb120b198f2a8528f97a9b0ae069","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"6180a296ca65b08a81914805cbc0f78da5f10a1f","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"ea0b5d0fe96356dce38f98375a57c52a04e13712","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"83bcf9228b0501694fb2589ed1d142855a2887f2","versionType":"git"},{"version":"0cfdd8f92cac01afbb12e4500514036a2b78756b","status":"affected","lessThan":"5a8db80f721deee8e916c2cfdee78decda02ce4f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/smc/smc_clc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.11","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.140","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.86","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.27","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.4","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/smc/smc_clc.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/257cdf0c5ced9c0fba8aba501d94b0a5fcef2086"},{"url":"https://git.kernel.org/stable/c/22546729b96fc873b23065dc49e3d73c45cfb874"},{"url":"https://git.kernel.org/stable/c/5eedbfd82c2884e0010fdfb3c9446a6ebcadb691"},{"url":"https://git.kernel.org/stable/c/f0858e1d5624bb120b198f2a8528f97a9b0ae069"},{"url":"https://git.kernel.org/stable/c/6180a296ca65b08a81914805cbc0f78da5f10a1f"},{"url":"https://git.kernel.org/stable/c/ea0b5d0fe96356dce38f98375a57c52a04e13712"},{"url":"https://git.kernel.org/stable/c/83bcf9228b0501694fb2589ed1d142855a2887f2"},{"url":"https://git.kernel.org/stable/c/5a8db80f721deee8e916c2cfdee78decda02ce4f"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The SMC CLC handshake runs over a TCP connection; a remote peer (a malicious client connecting to a listening SMC server, or a malicious server) triggers the dereference by sending a crafted DECLINE message, so the code is reachable purely over the network.\nAC:L - The attacker reliably crafts a DECLINE message with the SMC_FIRST_CONTACT_MASK bit set; the lgr==NULL condition is the default early-handshake state (the first message the server processes), so there is no race or condition outside attacker control.\nPR:N - On the server-side listen path the dereference occurs while processing the very first handshake message, before any authentication, so an unauthenticated remote peer requires no privileges.\nUI:N - A server with an AF_SMC listening socket processes the malicious handshake passively in a work queue with no local user action required.\nS:U - The crash is confined to the kernel's own security scope; no boundary (VM/IOMMU/sandbox) is crossed.\nC:N - This is a NULL pointer dereference with no information disclosure — no kernel memory contents are read or leaked.\nI:N - The write is to NULL plus a small fixed bitfield offset on a never-initialized pointer (not a controllable/dangling pointer), so it only crashes and provides no exploitable write primitive.\nA:H - Dereferencing the NULL lgr pointer causes a kernel oops/panic, taking down the system in a remotely-triggerable, unauthenticated denial of service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:29:12.274Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.6.140"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.12.86"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.18.27"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"7.0.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-46027","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:18:59.897964Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-617","lang":"en","type":"CWE","description":"CWE-617 Reachable Assertion"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:26:41.717Z"}}]}}}