{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90413", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.813Z", "datePublished": "2026-09-17T16:09:39.383Z", "dateUpdated": "2026-10-19T09:03:17.470Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:03:17.470Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nIB/isert: reject login PDUs declaring more data than was received\n\nisert_login_recv_done() records how many bytes the HCA actually placed in\nthe login buffer, but nothing compares that against the length the login\nPDU's BHS declares. isert_rx_login_req() copies min(login_req_len,\nMAX_KEY_VALUE_PAIRS) bytes into login->req_buf, and the login code then\nreads the declared length back out of that buffer - for the first PDU in\niscsi_target_locate_portal(),\n\n\tpayload_length = ntoh24(login_req->dlength);\n\ttmpbuf = kmemdup_nul(login->req_buf, payload_length, GFP_KERNEL);\n\nand for the ones after it in iscsi_decode_text_input(), reached from\niscsi_target_do_login().\n\nlogin->req_buf is a fixed MAX_KEY_VALUE_PAIRS (8192) byte allocation, so\nan initiator that declares more than it sends reads off the end of it,\nbefore authentication and with the length under its control:\n\n BUG: KASAN: slab-out-of-bounds in kmemdup_nul+0x43/0x80\n Read of size 8193 at addr ffff8881056a8000 by task iscsi_np/167\n __asan_memcpy+0x23/0x60\n kmemdup_nul+0x43/0x80\n iscsi_target_locate_portal+0x48d/0x1180\n iscsi_target_login_thread+0x19a9/0x3350\n Allocated by task 167:\n __kmalloc_cache_noprof+0x158/0x370\n iscsi_target_login_thread+0x971/0x3350\n which belongs to the cache kmalloc-8k of size 8192\n allocated 8192-byte region\n\nFalsifying the second login PDU instead reaches the other reader, on the\nsame buffer:\n\n BUG: KASAN: slab-out-of-bounds in kmemdup_nul+0x43/0x80\n Read of size 8193 at addr ffff888104d10000 by task kworker/1:1/50\n Workqueue: isert_login_wq iscsi_target_do_login_rx\n __asan_memcpy+0x23/0x60\n kmemdup_nul+0x43/0x80\n iscsi_decode_text_input+0xc6/0x11c0\n iscsi_target_do_login+0x261/0x1470\n iscsi_target_do_login_rx+0x51d/0x7d0\n\niscsit over TCP is not exposed: iscsit_get_login_rx() validates the\ndeclared length with iscsi_target_check_login_request() and then reads\nexactly that many bytes off the socket, so the declared length governs\nhow much arrives rather than how much is copied out of an already-filled\nbuffer. isert does not call iscsi_target_check_login_request() at all.\n\nReject a login PDU whose declared DataSegmentLength exceeds what was\nreceived, in both paths that reach isert_rx_login_req():\nisert_get_login_rx() for the first login PDU and isert_login_recv_done()\nfor the ones after it. dlength <= login_req_len is allowed because the\nreceived count can include up to three bytes of iSCSI padding.\n\nOnce the check is in place the copy out can no longer exceed the copy in:\nthe posted login SGE is ISER_RX_PAYLOAD_SIZE, so login_req_len cannot\nexceed MAX_KEY_VALUE_PAIRS and the min() in isert_rx_login_req() is\nlogin_req_len.\n\nLike the existing short-PDU check added by 29e7b925ae6d, the reject in\nisert_login_recv_done() returns without completing login_req_comp, so a\nmalformed subsequent PDU leaves the login to be torn down by the login\ntimer rather than failing immediately. The first-PDU path returns an\nerror and fails straight away.\n\nReproduced on 7.2.0-rc4 with soft-RoCE (rdma_rxe) under KASAN, using an\ninitiator that sends the real key=value payload while declaring 8193 in\nthe BHS, on the first login PDU and on the second in separate runs. The\nreported read size tracks the declared value exactly; 16384 and 61440\nbehave the same. Unpatched 3 of 3 runs report on each of the two paths,\npatched 0 of 3 on both, run alternately in a single session, and a normal\nlogin still completes on the patched build." } ], "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 forged length is the iSCSI Login Request BHS DataSegmentLength (hdr->dlength) delivered in an RDMA Send that completes in isert_login_recv_done(); isert_setup_id() rdma_bind_addr()/rdma_listen()s that portal on an IP sockaddr with RDMA_PS_TCP (RoCEv2/iWARP), so the bytes arrive on a routable IP transport.\nAC:L - The initiator sets dlength independently of wc->byte_len. isert_rx_login_req() copies only min(login_req_len, MAX_KEY_VALUE_PAIRS) into login->req_buf, then iscsi_target_locate_portal()/iscsi_decode_text_input() pass ntoh24(dlength) to kmemdup_nul(); declared lengths 8193, 16384 and 61440 hit with no race.\nPR:N - iscsi_target_locate_portal() runs in iscsi_target_login_thread() immediately after isert_get_login_rx() returns the first Login Request, before iscsi_target_start_negotiation() or CHAP; isert_connect_request() accepts the RDMA CM CONNECT_REQUEST whenever np->enabled, with no credentials.\nUI:N - The attacker itself performs the RDMA CM connect and sends the crafted Login Request; no local user action is required once the isert portal is already listening.\nS:U - kmemdup_nul() over-reads the host kernel's login->req_buf in iscsi_target_locate_portal() and iscsi_decode_text_input() on the iSER target; the impact stays in that kernel and does not cross a guest/host or IOMMU boundary.\nC:H - ntoh24(login_req->dlength) is a 24-bit attacker-chosen size passed to kmemdup_nul(login->req_buf, payload_length), which memcpy-reads that many bytes from the 8192-byte req_buf object, an unbounded slab-out-of-bounds read of adjacent kernel memory rather than a few-byte leak.\nI:N - kmemdup_nul() writes only into a newly allocated tmpbuf of size payload_length+1, so the bug is a source over-read of req_buf, not a write into neighboring objects; parsing that copy as key=value does not give the initiator an attacker-controlled kernel write.\nA:H - KASAN reports a slab-out-of-bounds read in kmemdup_nul() from iscsi_target_locate_portal() on the first PDU and from iscsi_decode_text_input() on later PDUs; a declared length of 61440 walks tens of kilobytes past the kmalloc-8k object and faults the target." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/ulp/isert/ib_isert.c" ], "versions": [ { "version": "b8d26b3be8b33682cf163274ed07479a70554633", "lessThan": "b1f3313e7b3e396e4985fea5c709477387e0a065", "status": "affected", "versionType": "git" }, { "version": "b8d26b3be8b33682cf163274ed07479a70554633", "lessThan": "228aaa620fe6a7bc8b5b21dd348b4836b1760c61", "status": "affected", "versionType": "git" }, { "version": "b8d26b3be8b33682cf163274ed07479a70554633", "lessThan": "0d9c0586af703890afe1bd0cfe641e3a3af1c32d", "status": "affected", "versionType": "git" }, { "version": "b8d26b3be8b33682cf163274ed07479a70554633", "lessThan": "44fe800ec13386c88bd5b32bcd1deaa1e17535d5", "status": "affected", "versionType": "git" }, { "version": "b8d26b3be8b33682cf163274ed07479a70554633", "lessThan": "71ec8bbfa4a183f1e623662f9cfbcd702e433bdb", "status": "affected", "versionType": "git" }, { "version": "b8d26b3be8b33682cf163274ed07479a70554633", "lessThan": "c345d9d0b3eefc990bb90cf565325785aab06aab", "status": "affected", "versionType": "git" }, { "version": "b8d26b3be8b33682cf163274ed07479a70554633", "lessThan": "48812c8103071d550d9ab4a3431be5bdc52255bc", "status": "affected", "versionType": "git" }, { "version": "b8d26b3be8b33682cf163274ed07479a70554633", "lessThan": "2488b5b4827e5415768afc8daf097e8eb83c98df", "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/infiniband/ulp/isert/ib_isert.c" ], "versions": [ { "version": "3.10", "status": "affected" }, { "version": "0", "lessThan": "3.10", "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": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "3.10", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/b1f3313e7b3e396e4985fea5c709477387e0a065" }, { "url": "https://git.kernel.org/stable/c/228aaa620fe6a7bc8b5b21dd348b4836b1760c61" }, { "url": "https://git.kernel.org/stable/c/0d9c0586af703890afe1bd0cfe641e3a3af1c32d" }, { "url": "https://git.kernel.org/stable/c/44fe800ec13386c88bd5b32bcd1deaa1e17535d5" }, { "url": "https://git.kernel.org/stable/c/71ec8bbfa4a183f1e623662f9cfbcd702e433bdb" }, { "url": "https://git.kernel.org/stable/c/c345d9d0b3eefc990bb90cf565325785aab06aab" }, { "url": "https://git.kernel.org/stable/c/48812c8103071d550d9ab4a3431be5bdc52255bc" }, { "url": "https://git.kernel.org/stable/c/2488b5b4827e5415768afc8daf097e8eb83c98df" } ], "title": "IB/isert: reject login PDUs declaring more data than was received", "x_generator": { "engine": "bippy-1.2.0" } } } }