CVE-2026-98366RDMA/rxe: validate access flags before swapping the MR's PD
Updated under an hour ago ()
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It affects Linux. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 0.12%, higher than 2% of scored CVEs.
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In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: validate access flags before swapping the MR's PD rxe_rereg_user_mr() reassigns mr->ibmr.pd first and only then validates the IB_MR_REREG_ACCESS argument: if (flags & IB_MR_REREG_PD) { rxe_put(old_pd); rxe_get(pd); mr->ibmr.pd = ibpd; } if (flags & IB_MR_REREG_ACCESS) { if (access & ~RXE_ACCESS_SUPPORTED_MR) return ERR_PTR(-EOPNOTSUPP); mr->access = access; } Both flags pass the entry check because RXE_MR_REREG_SUPPORTED is IB_MR_REREG_PD | IB_MR_REREG_ACCESS, so a caller can reach the access check with mr->ibmr.pd already reassigned. mr->ibmr.pd is owned by the core, which adjusts pd->usecnt only on the success path: ib_uverbs_rereg_mr() jumps to put_new_uobj on a driver error without undoing the reassignment, so mr->pd == new_pd while the usecnts still charge the MR to orig_pd. ib_dereg_mr_user() then decrements new_pd, whose count can reach zero while a memory window still references it; uverbs_free_pd() frees the PD on that count alone and rxe_mw_cleanup() writes to freed memory: BUG: KASAN: slab-use-after-free in __rxe_put+0x31/0xa0 Write of size 4 at addr ffff8881301dd690 by task rxe_poc/591 __rxe_put+0x31/0xa0 rxe_mw_cleanup+0x42/0x200 __rxe_cleanup+0x115/0x370 rxe_dealloc_mw+0x4c/0x80 Allocated by task 591: ib_uverbs_alloc_pd+0x258/0x540 Freed by task 591: ib_dealloc_pd_user+0x174/0x210 uverbs_free_pd+0x8d/0xc0 ib_uverbs_dealloc_pd+0x18e/0x1d0 Validate the access flags before mutating any state so the callback either applies every requested change or none.
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 0.12% (percentile 2)
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Oct 7, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | 544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c builds before 08f12745cb72981aa2cabe214af0c7a42a856f0a; from 544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c before 7230cc456d4bb2221c20c5f1d22b38b8576aa16f; from 544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c before fe602c91a52e161ace4afd5bdb8f33270c554c6f; 544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c builds before 4dd7a53f1c5b44693c26dac4b9b5bd5bb9d604c8; from 544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c before ae36a5b609ae79f4de966328b78d2584be9719a4 | CNA record |
References
- https://git.kernel.org/stable/c/08f12745cb72981aa2cabe214af0c7a42a856f0a
- https://git.kernel.org/stable/c/7230cc456d4bb2221c20c5f1d22b38b8576aa16f
- https://git.kernel.org/stable/c/fe602c91a52e161ace4afd5bdb8f33270c554c6f
- https://git.kernel.org/stable/c/4dd7a53f1c5b44693c26dac4b9b5bd5bb9d604c8
- https://git.kernel.org/stable/c/ae36a5b609ae79f4de966328b78d2584be9719a4
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.