{"id":"CVE-2026-43494","state":"PUBLISHED","title":"net/rds: reset op_nents when zerocopy page pin fails","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/rds: reset op_nents when zerocopy page pin fails\n\nWhen iov_iter_get_pages2() fails in rds_message_zcopy_from_user(),\nthe pinned pages are released with put_page(), and\nrm->data.op_mmp_znotifier is cleared.  But we fail to properly\nclear rm->data.op_nents.\n\nLater when rds_message_purge() is called from rds_sendmsg() the\ncleanup loop iterates over the incorrectly non zero number of\nop_nents and frees them again.\n\nFix this by properly resetting op_nents when it should be in\nrds_message_zcopy_from_user().","publishedAt":"2026-05-21T10:49:21.310Z","updatedAt":"2026-10-19T19:26:37.859Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"c6e51512a784c4a7b86e1a044988696e3b3721fa","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"03014551938a0887fa55f18ce49b70158a9c0113","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"d84ce1786ce40fdd3dd98db47aec5527817e1ef6","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"9115669faedccdda100428e2d26fd0aac8c50799","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"0bbbff00a15b1df2cac9014d6cf4b6890f473353","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"640e37f58f991546a87540d067279c2c1fa9fe51","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"290e833d1acb1093bc121fcdc97f5e6161157479","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"e174929793195e0cd6a4adb0cad731b39f9019b4","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rds/message.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.17","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":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","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/rds/message.c"]}],"references":["https://git.kernel.org/stable/c/c6e51512a784c4a7b86e1a044988696e3b3721fa","https://git.kernel.org/stable/c/03014551938a0887fa55f18ce49b70158a9c0113","https://git.kernel.org/stable/c/d84ce1786ce40fdd3dd98db47aec5527817e1ef6","https://git.kernel.org/stable/c/9115669faedccdda100428e2d26fd0aac8c50799","https://git.kernel.org/stable/c/0bbbff00a15b1df2cac9014d6cf4b6890f473353","https://git.kernel.org/stable/c/640e37f58f991546a87540d067279c2c1fa9fe51","https://git.kernel.org/stable/c/290e833d1acb1093bc121fcdc97f5e6161157479","https://git.kernel.org/stable/c/e174929793195e0cd6a4adb0cad731b39f9019b4","https://github.com/v12-security/pocs/tree/main/pintheft","http://www.openwall.com/lists/oss-security/2026/05/21/2","https://access.redhat.com/security/cve/CVE-2026-43494","https://bugzilla.redhat.com/show_bug.cgi?id=2480434","https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43494.json"],"weaknesses":["CWE-1341","CWE-415"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43494.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43494","state":"PUBLISHED","datePublished":"2026-05-21T10:49:21.310Z","dateUpdated":"2026-10-19T19:26:37.859Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:56.013Z"},"containers":{"cna":{"title":"net/rds: reset op_nents when zerocopy page pin fails","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/rds: reset op_nents when zerocopy page pin fails\n\nWhen iov_iter_get_pages2() fails in rds_message_zcopy_from_user(),\nthe pinned pages are released with put_page(), and\nrm->data.op_mmp_znotifier is cleared.  But we fail to properly\nclear rm->data.op_nents.\n\nLater when rds_message_purge() is called from rds_sendmsg() the\ncleanup loop iterates over the incorrectly non zero number of\nop_nents and frees them again.\n\nFix this by properly resetting op_nents when it should be in\nrds_message_zcopy_from_user()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"c6e51512a784c4a7b86e1a044988696e3b3721fa","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"03014551938a0887fa55f18ce49b70158a9c0113","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"d84ce1786ce40fdd3dd98db47aec5527817e1ef6","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"9115669faedccdda100428e2d26fd0aac8c50799","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"0bbbff00a15b1df2cac9014d6cf4b6890f473353","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"640e37f58f991546a87540d067279c2c1fa9fe51","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"290e833d1acb1093bc121fcdc97f5e6161157479","versionType":"git"},{"version":"0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3","status":"affected","lessThan":"e174929793195e0cd6a4adb0cad731b39f9019b4","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rds/message.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.17","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":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","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/rds/message.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c6e51512a784c4a7b86e1a044988696e3b3721fa"},{"url":"https://git.kernel.org/stable/c/03014551938a0887fa55f18ce49b70158a9c0113"},{"url":"https://git.kernel.org/stable/c/d84ce1786ce40fdd3dd98db47aec5527817e1ef6"},{"url":"https://git.kernel.org/stable/c/9115669faedccdda100428e2d26fd0aac8c50799"},{"url":"https://git.kernel.org/stable/c/0bbbff00a15b1df2cac9014d6cf4b6890f473353"},{"url":"https://git.kernel.org/stable/c/640e37f58f991546a87540d067279c2c1fa9fe51"},{"url":"https://git.kernel.org/stable/c/290e833d1acb1093bc121fcdc97f5e6161157479"},{"url":"https://git.kernel.org/stable/c/e174929793195e0cd6a4adb0cad731b39f9019b4"},{"url":"https://github.com/v12-security/pocs/tree/main/pintheft"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Triggered entirely by a local `sendmsg(MSG_ZEROCOPY)` syscall operating on the sending process's own user memory; a remote peer has no control over the page-pinning that fails, so it is not network-reachable.\nAC:L - The attacker fully controls the iovec layout and can deterministically pin one valid segment then point a later segment at unmapped memory to force `iov_iter_get_pages2()` to fail with `op_nents>=1`; no race or uncontrolled condition.\nPR:L - `rds_create()` performs no capability check, so any unprivileged local user can open the AF_RDS socket and reach the zerocopy send path; no real root or CAP needed.\nUI:N - The attacker performs the entire socket/setsockopt/sendmsg sequence themselves; no victim action is required.\nS:U - The corruption is within the kernel's own page-management security authority; there is no VM, IOMMU, or sandbox boundary crossed.\nC:H - The refcount underflow frees a page still mapped in the attacker's address space; once reused for other kernel/process data it remains readable through the stale mapping, enabling arbitrary memory disclosure.\nI:H - The same stale-mapping primitive permits writing into reallocated pages (page tables, slab, other tasks' memory), yielding an arbitrary-write/control-flow-hijack primitive suitable for privilege escalation.\nA:H - The double-free / page reference-count underflow corrupts kernel page state and reliably causes oops/panic, a full availability impact."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:28:17.738Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.17","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"http://www.openwall.com/lists/oss-security/2026/05/21/2"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2026-05-21T15:04:20.704Z"}},{"title":"kernel: net/rds: reset op_nents when zerocopy page pin fails","descriptions":[{"lang":"en","value":"A flaw was found in the Linux kernel, specifically within the `net/rds` module. When a zerocopy page pin operation fails, a counter used for memory management (`op_nents`) is not correctly reset. This can result in a double-free vulnerability, where the same memory is released twice. A local attacker could potentially exploit this to cause the system to crash (denial of service) or, in some cases, execute unauthorized code."}],"affected":[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","packageName":"kernel","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:10"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","packageName":"kernel","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:6"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","packageName":"kernel","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:7"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","packageName":"kernel-rt","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:7"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","packageName":"kernel","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","packageName":"kernel-rt","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","packageName":"kernel","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:9"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","packageName":"kernel-rt","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:9"]}],"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-43494","tags":["vdb-entry","x_refsource_REDHAT"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2480434","name":"RHBZ#2480434","tags":["issue-tracking","x_refsource_REDHAT"]},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43494.json","tags":["x_sadp-csaf-vex"]}],"metrics":[{"other":{"content":{"namespace":"https://access.redhat.com/security/updates/classification/","value":"Important"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":7,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1341","description":"Multiple Releases of Same Resource or Handle","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"redhat-SADP","orgId":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c","dateUpdated":"2026-07-15T00:55:52.893Z"},"datePublic":"2026-05-21T00:00:00.000Z","timeline":[{"lang":"en","time":"2026-05-21T00:00:00.000Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-05-21T00:00:00.000Z","value":"Made public."}],"x_adpType":"supplier","x_generator":{"engine":"sadp-cli 1.0.0"}},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-43494","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:17:47.906032Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-415","lang":"en","type":"CWE","description":"CWE-415 Double Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:26:37.859Z"}}]}}}