CVE-2026-98366
RDMA/rxe: validate access flags before swapping the MR's PD
No known exploitation. EPSS puts it in the 2nd percentile. Fixed versions are out.
What to do
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- LinuxAffected: ≥ 544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c, < 08f12745cb72981aa2cabe214af0c7a42a856f0aUpgrade to: 08f12745cb72981aa2cabe214af0c7a42a856f0aAffected: ≥ 544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c, < 7230cc456d4bb2221c20c5f1d22b38b8576aa16fUpgrade to: 7230cc456d4bb2221c20c5f1d22b38b8576aa16fAffected: ≥ 544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c, < fe602c91a52e161ace4afd5bdb8f33270c554c6fUpgrade to: fe602c91a52e161ace4afd5bdb8f33270c554c6fAffected: ≥ 544c7f62cf32db2bd358f1e8a40a98bf98fa2a5c, < 4dd7a53f1c5b44693c26dac4b9b5bd5bb9d604c8Upgrade to: 4dd7a53f1c5b44693c26dac4b9b5bd5bb9d604c8 + 1 more branchStated by: CVE record
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.1% chance of exploitation activity in the next 30 days, which ranks it in the 2nd percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
3 events over 1 day, from the signal feeds we watch.
- Record updated
- Publishedrecord updated
Affected products
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Scored 7.8 by NVD.
How it is reached
- Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required LowRequires basic user-level privileges
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Sources
References in the record
- git.kernel.org/stable/c/08f12745cb72981aa2cabe214af0c7a42a856f0a
- git.kernel.org/stable/c/4dd7a53f1c5b44693c26dac4b9b5bd5bb9d604c8
- git.kernel.org/stable/c/7230cc456d4bb2221c20c5f1d22b38b8576aa16f
And 2 more references. See all after sign-in
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