{"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":"2026-10-07T06:50:19.619Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-10-07T06:50:19.619Z"},"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-rc4","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-rc4"}]}]}],"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"}}}}