{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90011","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.781Z","datePublished":"2026-09-16T10:33:18.793Z","dateUpdated":"2026-09-16T14:41:28.132Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-16T14:41:28.132Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: target: iscsi: Reserve a terminator byte for the login payload\n\niscsi_target_check_login_request() rejects a login PDU whose\nDataSegmentLength exceeds MAX_KEY_VALUE_PAIRS, but the test is '>' and\nlogin->req_buf is allocated with exactly MAX_KEY_VALUE_PAIRS\nbytes. Since iscsit_get_login_rx() receives payload_length + padding\nbytes, where\n\n\tpadding = ((-payload_length) & 3);\n\nany payload_length from 8189 to 8192 fills the whole 8192 byte\nbuffer. The write stays in bounds, but no byte is left for a NUL\nterminator.\n\nThe buffer is subsequently consumed as a C string. In the CHAP path\nchap_check_algorithm() calls kstrdup(a_str), and extract_param() calls\nstrstr(in_buf, pattern) followed by strlen_semi(), none of which take a\nlength. convert_null_to_semi() additionally rewrites every embedded NUL\nto ';', so even a payload made of well formed NUL separated key=value\nrecords is left without a terminator. These walk past the end of the\nobject into adjacent slab memory. It is reachable by an unauthenticated\ninitiator against a portal configured for CHAP; when authentication is\nnot required iscsi_login_zero_tsih_s2() rewrites AuthMethod to None and\nthe CHAP path is never entered.\n\nAllocate one extra byte. kzalloc() zeroes it and nothing ever writes to\nit, as every writer copies to offset 0 for at most MAX_KEY_VALUE_PAIRS\nbytes, so the buffer is always terminated."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","baseScore":9.1,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The LIO in-kernel iSCSI target accepts remote TCP connections on the iSCSI portal (typically port 3260); a crafted Login PDU is received by iscsit_accept_np()/iscsit_get_login_rx() and reaches the CHAP parsers over the network, the same exposure model as nfsd or ksmbd.\nAC:L - The attacker fully controls DataSegmentLength and the login payload. A CHAP_A PDU of 8189-8192 bytes with no NUL, or a second CHAP round where convert_null_to_semi() strips every terminator, makes kstrdup()/strstr() over-read adjacent slab deterministically; no race or victim-side layout is required.\nPR:N - The over-read runs in the CHAP login handshake before the password hash is checked, so no Linux account or capability is needed. Default TPG authentication is CHAP (TA_AUTHENTICATION=1), and chap_server_open() proceeds once target-side CHAP credentials exist, which is the normal CHAP deployment.\nUI:N - The attacker opens a TCP connection to the listening portal and sends the malicious Login PDUs; no victim user action such as mounting a volume or accepting a prompt is required.\nS:U - The unbounded C-string over-read and any resulting kernel oops stay inside the host iSCSI target's kernel security authority and do not by themselves cross a VM, IOMMU, or sandbox boundary.\nC:H - chap_check_algorithm() kstrdup()s the unterminated 8192-byte req_buf, and extract_param() uses unbounded strstr()/strlen_semi() after convert_null_to_semi() removes embedded NULs, producing an unbounded out-of-bounds read of adjacent kmalloc-8k slab that can disclose neighboring kernel objects.\nI:N - iscsit_get_login_rx() copies at most MAX_KEY_VALUE_PAIRS bytes into req_buf, so the network write stays in bounds; convert_null_to_semi() also writes only within payload_length. There is no out-of-bounds write or control-flow hijack primitive.\nA:H - strlen()/kstrdup()/strstr() walking past the kmalloc-8k login object into unmapped or guard pages causes a kernel oops, and the attacker can repeat the unauthenticated login against an exposed portal, denying service to the host and its iSCSI clients."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/target/iscsi/iscsi_target_login.c"],"versions":[{"version":"e48354ce078c079996f89d715dfa44814b4eba01","lessThan":"5fac79f248c37774d1dd761406f83d25ca6ff8e4","status":"affected","versionType":"git"},{"version":"e48354ce078c079996f89d715dfa44814b4eba01","lessThan":"6ddddcad436d8e6e619204d3c848147ff2f5bf1e","status":"affected","versionType":"git"},{"version":"e48354ce078c079996f89d715dfa44814b4eba01","lessThan":"b19dc17ed963ac36c0db4b52a1803fb11169f91f","status":"affected","versionType":"git"},{"version":"e48354ce078c079996f89d715dfa44814b4eba01","lessThan":"6b589ef9d5f6cdc70d2b4f269ca6cf26b5ebb076","status":"affected","versionType":"git"},{"version":"e48354ce078c079996f89d715dfa44814b4eba01","lessThan":"eb9dadf4d552ebe10644871c5189286552aa48f5","status":"affected","versionType":"git"},{"version":"e48354ce078c079996f89d715dfa44814b4eba01","lessThan":"1624bff4c5118ad494d50ad94d44f22064667a7f","status":"affected","versionType":"git"},{"version":"e48354ce078c079996f89d715dfa44814b4eba01","lessThan":"3ddf3ea291a0ef2ea93b82e158960ac2cc42302b","status":"affected","versionType":"git"},{"version":"e48354ce078c079996f89d715dfa44814b4eba01","lessThan":"f4825922d2fb371e2b969697d792077f1b62b62c","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/target/iscsi/iscsi_target_login.c"],"versions":[{"version":"3.1","status":"affected"},{"version":"0","lessThan":"3.1","status":"unaffected","versionType":"semver"},{"version":"5.10.270","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.221","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.188","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.157","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.110","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.51","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.5","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.1","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.1","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.1","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.1","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.1","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.1","versionEndExcluding":"6.18.51"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.1","versionEndExcluding":"7.2.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.1","versionEndExcluding":"7.3-rc2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/5fac79f248c37774d1dd761406f83d25ca6ff8e4"},{"url":"https://git.kernel.org/stable/c/6ddddcad436d8e6e619204d3c848147ff2f5bf1e"},{"url":"https://git.kernel.org/stable/c/b19dc17ed963ac36c0db4b52a1803fb11169f91f"},{"url":"https://git.kernel.org/stable/c/6b589ef9d5f6cdc70d2b4f269ca6cf26b5ebb076"},{"url":"https://git.kernel.org/stable/c/eb9dadf4d552ebe10644871c5189286552aa48f5"},{"url":"https://git.kernel.org/stable/c/1624bff4c5118ad494d50ad94d44f22064667a7f"},{"url":"https://git.kernel.org/stable/c/3ddf3ea291a0ef2ea93b82e158960ac2cc42302b"},{"url":"https://git.kernel.org/stable/c/f4825922d2fb371e2b969697d792077f1b62b62c"}],"title":"scsi: target: iscsi: Reserve a terminator byte for the login payload","x_generator":{"engine":"bippy-1.2.0"}}}}