{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-46133", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.099Z", "datePublished": "2026-05-28T09:35:47.819Z", "dateUpdated": "2026-08-05T12:29:57.097Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:29:57.097Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable code processes RoCEv2 packets encapsulated in routable UDP/IP (port 4791); a remote attacker sends a single crafted UDP packet to the host running a Soft RoCE device, with no L2 adjacency required.\nAC:L - A single 48-byte packet with opcode 0xff and QPN=IB_MULTICAST_QPN deterministically triggers the underflowed length and OOB read; there is no race and no attacker-uncontrolled memory-layout dependency.\nPR:N - The OOB read occurs during ICRC validation before any QP lookup, connection, or credential check; the commit confirms it requires \"no QP, no connection, and no authentication.\"\nUI:N - Exploitation requires only that the attacker send a packet; no victim action is needed.\nS:U - The out-of-bounds read and resulting crash occur within the kernel's own security authority; no boundary (VM/IOMMU/sandbox) is crossed.\nC:N - The out-of-bounds bytes are fed into an internal CRC32 comparison and are never returned to or observable by the attacker, so no information is disclosed.\nI:N - The vulnerability is a read-only out-of-bounds access; no kernel memory is modified.\nA:H - The underflowed length drives crc32 across far out-of-bounds memory; subsequent packets fault on unmapped pages and panic the kernel, a reliable remote denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/infiniband/sw/rxe/rxe_recv.c" ], "versions": [ { "version": "8700e3e7c4857d28ebaa824509934556da0b3e76", "lessThan": "318787fa7193bd79691f2ebce4e80cb6abd0faef", "status": "affected", "versionType": "git" }, { "version": "8700e3e7c4857d28ebaa824509934556da0b3e76", "lessThan": "6a79b1ea0fcb2c998fda6a793050f66146e9cc42", "status": "affected", "versionType": "git" }, { "version": "8700e3e7c4857d28ebaa824509934556da0b3e76", "lessThan": "599cfdf44c1701c581cd4a21f1e1e03f8dc3840b", "status": "affected", "versionType": "git" }, { "version": "8700e3e7c4857d28ebaa824509934556da0b3e76", "lessThan": "e3dc3a2fb05f4ed49c7f20594c4c52350d032189", "status": "affected", "versionType": "git" }, { "version": "8700e3e7c4857d28ebaa824509934556da0b3e76", "lessThan": "f8ee926431a7bbec2b10c1290664af2cb290b983", "status": "affected", "versionType": "git" }, { "version": "8700e3e7c4857d28ebaa824509934556da0b3e76", "lessThan": "006a3a5f75345c6a0dbf13fd3ee01406e93b6733", "status": "affected", "versionType": "git" }, { "version": "8700e3e7c4857d28ebaa824509934556da0b3e76", "lessThan": "6fa18025e5782afff91415fd5217b39c1e4837d7", "status": "affected", "versionType": "git" }, { "version": "8700e3e7c4857d28ebaa824509934556da0b3e76", "lessThan": "4c6f86d85d03cdb33addce86aa69aa795ca6c47a", "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/sw/rxe/rxe_recv.c" ], "versions": [ { "version": "4.8", "status": "affected" }, { "version": "0", "lessThan": "4.8", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.258", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.209", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.140", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.88", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.30", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.7", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "4.8", "versionEndExcluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.6.140" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.12.88" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.18.30" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "7.0.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/318787fa7193bd79691f2ebce4e80cb6abd0faef" }, { "url": "https://git.kernel.org/stable/c/6a79b1ea0fcb2c998fda6a793050f66146e9cc42" }, { "url": "https://git.kernel.org/stable/c/599cfdf44c1701c581cd4a21f1e1e03f8dc3840b" }, { "url": "https://git.kernel.org/stable/c/e3dc3a2fb05f4ed49c7f20594c4c52350d032189" }, { "url": "https://git.kernel.org/stable/c/f8ee926431a7bbec2b10c1290664af2cb290b983" }, { "url": "https://git.kernel.org/stable/c/006a3a5f75345c6a0dbf13fd3ee01406e93b6733" }, { "url": "https://git.kernel.org/stable/c/6fa18025e5782afff91415fd5217b39c1e4837d7" }, { "url": "https://git.kernel.org/stable/c/4c6f86d85d03cdb33addce86aa69aa795ca6c47a" } ], "title": "RDMA/rxe: Reject unknown opcodes before ICRC processing", "x_generator": { "engine": "bippy-1.2.0" } } } }