{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-46325", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.112Z", "datePublished": "2026-06-09T12:25:52.792Z", "dateUpdated": "2026-08-05T12:31:20.551Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:31:20.551Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE\n\nThe current implementation incorrectly handles memory regions (MRs) with\npage sizes different from the system PAGE_SIZE. The core issue is that\nrxe_set_page() is called with mr->page_size step increments, but the\npage_list stores individual struct page pointers, each representing\nPAGE_SIZE of memory.\n\nib_sg_to_page() has ensured that when i>=1 either\na) SG[i-1].dma_end and SG[i].dma_addr are contiguous\nor\nb) SG[i-1].dma_end and SG[i].dma_addr are mr->page_size aligned.\n\nThis leads to incorrect iova-to-va conversion in scenarios:\n\n1) page_size < PAGE_SIZE (e.g., MR: 4K, system: 64K):\n ibmr->iova = 0x181800\n sg[0]: dma_addr=0x181800, len=0x800\n sg[1]: dma_addr=0x173000, len=0x1000\n\n Access iova = 0x181800 + 0x810 = 0x182010\n Expected VA: 0x173010 (second SG, offset 0x10)\n Before fix:\n - index = (0x182010 >> 12) - (0x181800 >> 12) = 1\n - page_offset = 0x182010 & 0xFFF = 0x10\n - xarray[1] stores system page base 0x170000\n - Resulting VA: 0x170000 + 0x10 = 0x170010 (wrong)\n\n2) page_size > PAGE_SIZE (e.g., MR: 64K, system: 4K):\n ibmr->iova = 0x18f800\n sg[0]: dma_addr=0x18f800, len=0x800\n sg[1]: dma_addr=0x170000, len=0x1000\n\n Access iova = 0x18f800 + 0x810 = 0x190010\n Expected VA: 0x170010 (second SG, offset 0x10)\n Before fix:\n - index = (0x190010 >> 16) - (0x18f800 >> 16) = 1\n - page_offset = 0x190010 & 0xFFFF = 0x10\n - xarray[1] stores system page for dma_addr 0x170000\n - Resulting VA: system page of 0x170000 + 0x10 = 0x170010 (wrong)\n\nYi Zhang reported a kernel panic[1] years ago related to this defect.\n\nSolution:\n1. Replace xarray with pre-allocated rxe_mr_page array for sequential\n indexing (all MR page indices are contiguous)\n2. Each rxe_mr_page stores both struct page* and offset within the\n system page\n3. Handle MR page_size != PAGE_SIZE relationships:\n - page_size > PAGE_SIZE: Split MR pages into multiple system pages\n - page_size <= PAGE_SIZE: Store offset within system page\n4. Add boundary checks and compatibility validation\n\nThis ensures correct iova-to-va conversion regardless of MR page size\nand system PAGE_SIZE relationship, while improving performance through\narray-based sequential access.\n\nTests on 4K and 64K PAGE_SIZE hosts:\n- rdma-core/pytests\n $ ./build/bin/run_tests.py --dev eth0_rxe\n- blktest:\n $ TIMEOUT=30 QUICK_RUN=1 USE_RXE=1 NVMET_TRTYPES=rdma ./check nvme srp rnbd\n\n[1] https://lore.kernel.org/all/CAHj4cs9XRqE25jyVw9rj9YugffLn5+f=1znaBEnu1usLOciD+g@mail.gmail.com/T/" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The bug is reached when rxe processes incoming RoCE packets over UDP (port 4791) on the responder path for RDMA Read, Write, and Atomic operations, which is the standard network-facing deployment for software RoCE storage targets and RDMA services.\nAC:L - Once a victim host runs rxe with an FMR whose page_size differs from PAGE_SIZE, a remote peer can reliably trigger the defective iova-to-VA conversion by sending RDMA operations with IOVAs that cross MR page boundaries, as demonstrated in the fix commit's worked examples.\nPR:N - Exploitation requires no OS privileges on the victim host; a remote attacker only needs network reachability to an established RDMA session (e.g., NVMe-oF or rtrs client) and a valid rkey from that connection, not local root or CAP_NET_ADMIN on the target system.\nUI:N - No victim user action is required beyond normal operation of an RDMA-connected service; the attacker triggers the flaw by sending crafted RDMA packets over an existing queue pair.\nS:U - Impact is confined to kernel memory corruption and crashes within the same kernel security boundary; this is not a VM escape, IOMMU bypass, or cross-authority sandbox breakout.\nC:H - Incorrect iova-to-VA mapping causes memcpy and atomic handlers to read from the wrong struct page, enabling disclosure of data from unintended pages within the MR mapping and constituting out-of-bounds kernel memory read.\nI:H - RDMA Write and Atomic Write operations using the buggy conversion write to incorrectly resolved virtual addresses, corrupting kernel memory outside the intended MR buffer and providing a memory-corruption primitive exploitable for further compromise.\nA:H - The fix commit cites a confirmed kernel panic from this defect, and misresolved page mappings in rxe_mr_copy() can cause oopses or crashes when accessing invalid or misaligned memory." } ] } ], "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_mr.c", "drivers/infiniband/sw/rxe/rxe_verbs.h" ], "versions": [ { "version": "592627ccbdff0ec6fff00fc761142a76db750dd4", "lessThan": "409c2c5508f3d30627bea576f8676de523cb906e", "status": "affected", "versionType": "git" }, { "version": "592627ccbdff0ec6fff00fc761142a76db750dd4", "lessThan": "836f6c13c9674027793f720be3f15ecd2b90b6ca", "status": "affected", "versionType": "git" }, { "version": "592627ccbdff0ec6fff00fc761142a76db750dd4", "lessThan": "12985e5915a0b8354796efadaaeb201eed115377", "status": "affected", "versionType": "git" }, { "version": "0e443760b8b7b1e6723f4408afa056b2bc4fea12", "status": "affected", "versionType": "git" }, { "version": "6.2.3", "lessThan": "6.3", "status": "affected", "versionType": "semver" } ] }, { "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_mr.c", "drivers/infiniband/sw/rxe/rxe_verbs.h" ], "versions": [ { "version": "6.3", "status": "affected" }, { "version": "0", "lessThan": "6.3", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.14", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.4", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "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": "6.3", "versionEndExcluding": "6.18.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "6.19.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "7.0" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/409c2c5508f3d30627bea576f8676de523cb906e" }, { "url": "https://git.kernel.org/stable/c/836f6c13c9674027793f720be3f15ecd2b90b6ca" }, { "url": "https://git.kernel.org/stable/c/12985e5915a0b8354796efadaaeb201eed115377" } ], "title": "RDMA/rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE", "x_generator": { "engine": "bippy-1.2.0" } } } }