{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98366", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.344Z", "datePublished": "2026-10-06T08:46:51.638Z", "dateUpdated": "2026-10-19T09:18:18.297Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:18:18.297Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: validate access flags before swapping the MR's PD\n\nrxe_rereg_user_mr() reassigns mr->ibmr.pd first and only then\nvalidates the IB_MR_REREG_ACCESS argument:\n\n\tif (flags & IB_MR_REREG_PD) {\n\t\trxe_put(old_pd);\n\t\trxe_get(pd);\n\t\tmr->ibmr.pd = ibpd;\n\t}\n\n\tif (flags & IB_MR_REREG_ACCESS) {\n\t\tif (access & ~RXE_ACCESS_SUPPORTED_MR)\n\t\t\treturn ERR_PTR(-EOPNOTSUPP);\n\t\tmr->access = access;\n\t}\n\nBoth flags pass the entry check because RXE_MR_REREG_SUPPORTED is\nIB_MR_REREG_PD | IB_MR_REREG_ACCESS, so a caller can reach the access\ncheck with mr->ibmr.pd already reassigned.\n\nmr->ibmr.pd is owned by the core, which adjusts pd->usecnt only on the\nsuccess path: ib_uverbs_rereg_mr() jumps to put_new_uobj on a driver error\nwithout undoing the reassignment, so mr->pd == new_pd while the usecnts\nstill charge the MR to orig_pd. ib_dereg_mr_user() then decrements\nnew_pd, whose count can reach zero while a memory window still references\nit; uverbs_free_pd() frees the PD on that count alone and rxe_mw_cleanup()\nwrites to freed memory:\n\n BUG: KASAN: slab-use-after-free in __rxe_put+0x31/0xa0\n Write of size 4 at addr ffff8881301dd690 by task rxe_poc/591\n __rxe_put+0x31/0xa0\n rxe_mw_cleanup+0x42/0x200\n __rxe_cleanup+0x115/0x370\n rxe_dealloc_mw+0x4c/0x80\n Allocated by task 591:\n ib_uverbs_alloc_pd+0x258/0x540\n Freed by task 591:\n ib_dealloc_pd_user+0x174/0x210\n uverbs_free_pd+0x8d/0xc0\n ib_uverbs_dealloc_pd+0x18e/0x1d0\n\nValidate the access flags before mutating any state so the callback either\napplies every requested change or none." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bad access_flags/pd_handle reach rxe_rereg_user_mr() only through a local IB_USER_VERBS_CMD_REREG_MR on /dev/infiniband/uverbsN via ib_uverbs_rereg_mr(); no RoCE packet carries rereg arguments, so a remote peer cannot drive it.\nAC:L - Deterministic: flags IB_MR_REREG_PD|IB_MR_REREG_ACCESS with access=IB_ACCESS_RELAXED_ORDERING passes core ib_check_mr_access() but fails RXE_ACCESS_SUPPORTED_MR after mr->ibmr.pd was swapped; the attacker then deregs the MR and deallocs the PD its own MW still uses. No race.\nPR:L - uverbs_devnode() creates /dev/infiniband/uverbsN mode 0666 and there is no capability check from ib_uverbs_rereg_mr() to rxe_rereg_user_mr(); any unprivileged local user owning a PD/MR/MW triggers it. Only the one-time admin rxe link creation (RDMA_NL_ADMIN_PERM) is needed.\nUI:N - The attacker's own process issues alloc_pd, reg_mr, alloc_mw, the failing rereg_mr, dereg_mr and dealloc_pd; no other user or administrator action is involved.\nS:U - The freed rxe PD and the corrupted refcounts are kernel heap objects within the same kernel security authority; no VM, IOMMU or sandbox boundary is crossed.\nC:H - After uverbs_free_pd() frees the PD on usecnt alone, the surviving MW still holds a dangling pointer to it; reclaiming that slab object with sprayed data turns later accesses through the MW into a use-after-free read of attacker-shaped memory.\nI:H - rxe_mw_cleanup() -> __rxe_put() writes (refcount decrement, KASAN write of size 4) into the freed PD, and the inconsistent mr->pd vs usecnt state can be repeated; a decrement into reallocated slab memory is a usable corruption primitive toward privilege escalation.\nA:H - The use-after-free write in __rxe_put() during rxe_dealloc_mw() corrupts freed slab memory and can oops or panic the kernel, and an unprivileged user can repeat it at will." } ] } ], "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_verbs.c" ], "versions": [ { "version": "544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c", "lessThan": "08f12745cb72981aa2cabe214af0c7a42a856f0a", "status": "affected", "versionType": "git" }, { "version": "544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c", "lessThan": "7230cc456d4bb2221c20c5f1d22b38b8576aa16f", "status": "affected", "versionType": "git" }, { "version": "544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c", "lessThan": "fe602c91a52e161ace4afd5bdb8f33270c554c6f", "status": "affected", "versionType": "git" }, { "version": "544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c", "lessThan": "4dd7a53f1c5b44693c26dac4b9b5bd5bb9d604c8", "status": "affected", "versionType": "git" }, { "version": "544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c", "lessThan": "ae36a5b609ae79f4de966328b78d2584be9719a4", "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_verbs.c" ], "versions": [ { "version": "6.5", "status": "affected" }, { "version": "0", "lessThan": "6.5", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.158", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.112", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.54", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.8", "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": "6.5", "versionEndExcluding": "6.6.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "6.12.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "6.18.54" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "7.2.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/08f12745cb72981aa2cabe214af0c7a42a856f0a" }, { "url": "https://git.kernel.org/stable/c/7230cc456d4bb2221c20c5f1d22b38b8576aa16f" }, { "url": "https://git.kernel.org/stable/c/fe602c91a52e161ace4afd5bdb8f33270c554c6f" }, { "url": "https://git.kernel.org/stable/c/4dd7a53f1c5b44693c26dac4b9b5bd5bb9d604c8" }, { "url": "https://git.kernel.org/stable/c/ae36a5b609ae79f4de966328b78d2584be9719a4" } ], "title": "RDMA/rxe: validate access flags before swapping the MR's PD", "x_generator": { "engine": "bippy-1.2.0" } } } }