{"id":"CVE-2026-46133","revision":"1ab1745e8a104e4abd7235838d349dd0","records":[{"revision":"1ab1745e8a104e4abd7235838d349dd0","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-46133","aliases":[],"title":"RDMA/rxe: Reject unknown opcodes before ICRC processing","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: Reject unknown opcodes before ICRC processing\n\nEven after applying commit 7244491dab34 (\"RDMA/rxe: Validate pad and ICRC\nbefore payload_size() in rxe_rcv\"), a single unauthenticated UDP packet\ncan still trigger panic.  That patch handled payload_size() underflow only\nfor valid opcodes with short packets, not for packets carrying an unknown\nopcode.  The unknown-opcode OOB read described below predates that commit\nand reaches back to the initial Soft RoCE driver.\n\nThe check added there reads\n\n    pkt->paylen < header_size(pkt) + bth_pad(pkt) + RXE_ICRC_SIZE\n\nwhere header_size(pkt) expands to rxe_opcode[pkt->opcode].length.  The\nrxe_opcode[] array has 256 entries but is only populated for defined IB\nopcodes; any other entry (for example opcode 0xff) is zero-initialized, so\nlength == 0 and the check degenerates to\n\n    pkt->paylen < 0 + bth_pad(pkt) + RXE_ICRC_SIZE\n\nwhich does not constrain pkt->paylen enough.  rxe_icrc_hdr() then computes\n\n    rxe_opcode[pkt->opcode].length - RXE_BTH_BYTES\n\nwhich underflows when length == 0 and passes a huge value to rxe_crc32(),\ncausing an out-of-bounds read of the skb payload.\n\nReproduced on v7.0-rc7 with that fix applied, QEMU/KVM with\nCONFIG_RDMA_RXE=y and CONFIG_KASAN=y, after\n\n    rdma link add rxe0 type rxe netdev eth0\n\nA single 48-byte UDP packet to port 4791 with BTH opcode=0xff and\nQPN=IB_MULTICAST_QPN triggers:\n\n    BUG: KASAN: slab-out-of-bounds in crc32_le+0x115/0x170\n    Read of size 1 at addr ...\n    The buggy address is located 0 bytes to the right of\n     allocated 704-byte region\n    Call Trace:\n     crc32_le+0x115/0x170\n     rxe_icrc_hdr.isra.0+0x226/0x300\n     rxe_icrc_check+0x13f/0x3a0\n     rxe_rcv+0x6e1/0x16e0\n     rxe_udp_encap_recv+0x20a/0x320\n     udp_queue_rcv_one_skb+0x7ed/0x12c0\n\nSubsequent packets with the same shape fault on unmapped memory and panic\nthe kernel.  The trigger requires only module load and \"rdma link add\"; no\nQP, no connection, and no authentication.\n\nFix this by rejecting packets whose opcode has no rxe_opcode[] entry,\ndetected via the zero mask or zero length, before any length arithmetic\nruns.","state":0,"publishedAt":"2026-05-28T09:35:47.819+00:00","modifiedAt":"2026-10-19T19:36:51.685+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/sw/rxe/rxe_recv.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"8700e3e7c4857d28ebaa824509934556da0b3e76\",\n                            \"lessThan\": \"318787fa7193bd79691f2ebce4e80cb6abd0faef\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8700e3e7c4857d28ebaa824509934556da0b3e76\",\n                            \"lessThan\": \"6a79b1ea0fcb2c998fda6a793050f66146e9cc42\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8700e3e7c4857d28ebaa824509934556da0b3e76\",\n                            \"lessThan\": \"599cfdf44c1701c581cd4a21f1e1e03f8dc3840b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8700e3e7c4857d28ebaa824509934556da0b3e76\",\n                            \"lessThan\": \"e3dc3a2fb05f4ed49c7f20594c4c52350d032189\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8700e3e7c4857d28ebaa824509934556da0b3e76\",\n                            \"lessThan\": \"f8ee926431a7bbec2b10c1290664af2cb290b983\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8700e3e7c4857d28ebaa824509934556da0b3e76\",\n                            \"lessThan\": \"006a3a5f75345c6a0dbf13fd3ee01406e93b6733\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8700e3e7c4857d28ebaa824509934556da0b3e76\",\n                            \"lessThan\": \"6fa18025e5782afff91415fd5217b39c1e4837d7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8700e3e7c4857d28ebaa824509934556da0b3e76\",\n                            \"lessThan\": \"4c6f86d85d03cdb33addce86aa69aa795ca6c47a\",\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/sw/rxe/rxe_recv.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.8\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.8\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.258\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.209\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.175\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.140\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.88\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.30\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0.7\",\n                            \"lessThanOrEqual\": \"7.0.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1\",\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:N/I:N/A:H","score":7.5,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/318787fa7193bd79691f2ebce4e80cb6abd0faef","https://git.kernel.org/stable/c/6a79b1ea0fcb2c998fda6a793050f66146e9cc42","https://git.kernel.org/stable/c/599cfdf44c1701c581cd4a21f1e1e03f8dc3840b","https://git.kernel.org/stable/c/e3dc3a2fb05f4ed49c7f20594c4c52350d032189","https://git.kernel.org/stable/c/f8ee926431a7bbec2b10c1290664af2cb290b983","https://git.kernel.org/stable/c/006a3a5f75345c6a0dbf13fd3ee01406e93b6733","https://git.kernel.org/stable/c/6fa18025e5782afff91415fd5217b39c1e4837d7","https://git.kernel.org/stable/c/4c6f86d85d03cdb33addce86aa69aa795ca6c47a"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-46133","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-46133","identifiers":["CVE-2026-46133"]},"retained":false,"historicalAffected":[]}],"coverage":[]}