{"id":"CVE-2026-90413","revision":"83495d64c2a341d4bda89650b103d5f3","records":[{"revision":"83495d64c2a341d4bda89650b103d5f3","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-90413","aliases":[],"title":"IB/isert: reject login PDUs declaring more data than was received","description":"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.","state":0,"publishedAt":"2026-09-17T16:09:39.383+00:00","modifiedAt":"2026-10-19T09:03:17.47+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/infiniband/ulp/isert/ib_isert.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"b8d26b3be8b33682cf163274ed07479a70554633\",\n                            \"lessThan\": \"b1f3313e7b3e396e4985fea5c709477387e0a065\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b8d26b3be8b33682cf163274ed07479a70554633\",\n                            \"lessThan\": \"228aaa620fe6a7bc8b5b21dd348b4836b1760c61\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b8d26b3be8b33682cf163274ed07479a70554633\",\n                            \"lessThan\": \"0d9c0586af703890afe1bd0cfe641e3a3af1c32d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b8d26b3be8b33682cf163274ed07479a70554633\",\n                            \"lessThan\": \"44fe800ec13386c88bd5b32bcd1deaa1e17535d5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b8d26b3be8b33682cf163274ed07479a70554633\",\n                            \"lessThan\": \"71ec8bbfa4a183f1e623662f9cfbcd702e433bdb\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b8d26b3be8b33682cf163274ed07479a70554633\",\n                            \"lessThan\": \"c345d9d0b3eefc990bb90cf565325785aab06aab\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b8d26b3be8b33682cf163274ed07479a70554633\",\n                            \"lessThan\": \"48812c8103071d550d9ab4a3431be5bdc52255bc\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b8d26b3be8b33682cf163274ed07479a70554633\",\n                            \"lessThan\": \"2488b5b4827e5415768afc8daf097e8eb83c98df\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/infiniband/ulp/isert/ib_isert.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3.10\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"3.10\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.270\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.221\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.188\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.157\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.110\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.52\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.6\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","score":9.1,"severity":"CRITICAL"}],"references":["https://git.kernel.org/stable/c/b1f3313e7b3e396e4985fea5c709477387e0a065","https://git.kernel.org/stable/c/228aaa620fe6a7bc8b5b21dd348b4836b1760c61","https://git.kernel.org/stable/c/0d9c0586af703890afe1bd0cfe641e3a3af1c32d","https://git.kernel.org/stable/c/44fe800ec13386c88bd5b32bcd1deaa1e17535d5","https://git.kernel.org/stable/c/71ec8bbfa4a183f1e623662f9cfbcd702e433bdb","https://git.kernel.org/stable/c/c345d9d0b3eefc990bb90cf565325785aab06aab","https://git.kernel.org/stable/c/48812c8103071d550d9ab4a3431be5bdc52255bc","https://git.kernel.org/stable/c/2488b5b4827e5415768afc8daf097e8eb83c98df"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-90413","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-90413","identifiers":["CVE-2026-90413"]},"retained":false,"historicalAffected":[]}],"coverage":[]}