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Linux KernelOperating system · Linux

CVE-2026-46325

CRITICAL · 9.8 CVSS v3.1 Published 2026-06-09
Fix available
A fix is available. Upgrade to 6.18.14 / 6.19.4 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE The current implementation incorrectly handles memory regions (MRs) with page sizes different from the system PAGE_SIZE. The core issue is that rxe_set_page() is called with mr->page_size step increments, but the page_list stores individual struct page pointers, each representing PAGE_SIZE of memory. ib_sg_to_page() has ensured that when i>=1 either a) SG[i-1].dma_end and SG[i].dma_addr are contiguous or b) SG[i-1].dma_end and SG[i].dma_addr are mr->page_size aligned. This leads to incorrect iova-to-va conversion in scenarios: 1) page_size < PAGE_SIZE (e.g., MR: 4K, system: 64K): ibmr->iova = 0x181800 sg[0]: dma_addr=0x181800, len=0x800 sg[1]: dma_addr=0x173000, len=0x1000 Access iova = 0x181800 + 0x810 = 0x182010 Expected VA: 0x173010 (second SG, offset 0x10) Before fix: - index = (0x182010 >> 12) - (0x181800 >> 12) = 1 - page_offset = 0x182010 & 0xFFF = 0x10 - xarray[1] stores system page base 0x170000 - Resulting VA: 0x170000 + 0x10 = 0x170010 (wrong) 2) page_size > PAGE_SIZE (e.g., MR: 64K, system: 4K): ibmr->iova = 0x18f800 sg[0]: dma_addr=0x18f800, len=0x800 sg[1]: dma_addr=0x170000, len=0x1000 Access iova = 0x18f800 + 0x810 = 0x190010 Expected VA: 0x170010 (second SG, offset 0x10) Before fix: - index = (0x190010 >> 16) - (0x18f800 >> 16) = 1 - page_offset = 0x190010 & 0xFFFF = 0x10 - xarray[1] stores system page for dma_addr 0x170000 - Resulting VA: system page of 0x170000 + 0x10 = 0x170010 (wrong) Yi Zhang reported a kernel panic[1] years ago related to this defect. Solution: 1. Replace xarray with pre-allocated rxe_mr_page array for sequential indexing (all MR page indices are contiguous) 2. Each rxe_mr_page stores both struct page* and offset within the system page 3. Handle MR page_size != PAGE_SIZE relationships: - page_size > PAGE_SIZE: Split MR pages into multiple system pages - page_size <= PAGE_SIZE: Store offset within system page 4. Add boundary checks and compatibility validation This ensures correct iova-to-va conversion regardless of MR page size and system PAGE_SIZE relationship, while improving performance through array-based sequential access. Tests on 4K and 64K PAGE_SIZE hosts: - rdma-core/pytests $ ./build/bin/run_tests.py --dev eth0_rxe - blktest: $ TIMEOUT=30 QUICK_RUN=1 USE_RXE=1 NVMET_TRTYPES=rdma ./check nvme srp rnbd [1] https://lore.kernel.org/all/CAHj4cs9XRqE25jyVw9rj9YugffLn5+f=1znaBEnu1usLOciD+g@mail.gmail.com/T/

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The RDMA/rxe driver has a flaw in iova-to-virtual-address conversion when memory region page sizes differ from system PAGE_SIZE. The bug causes incorrect indexing into the page array, leading to wrong virtual address calculations that can trigger kernel panics or memory corruption.

MitigationApply the kernel patch that replaces xarray with a pre-allocated rxe_mr_page array and properly handles MR page size relationships with system PAGE_SIZE through offset tracking and boundary checks.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 6.2.3, < 6.18.14>= 6.19, < 6.19.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check kernel version
    Run 'uname -r' or 'cat /proc/version' to get the running kernel version
    Affected if The kernel version is >= 6.2.3 and < 6.18.14, OR >= 6.19 and < 6.19.4
  2. Verify rxe driver is loaded
    Run 'lsmod | grep rxe' or check 'ls /sys/module/ | grep rxe' to see if the RDMA/rxe (Soft RoCE) driver is loaded
    Affected if The rxe module is loaded into the kernel
  3. Check for active RDMA devices
    Run 'rdma link' or check 'ls /sys/class/infiniband/' to see if an rxe device exists
    Affected if An rxe (Soft RoCE) RDMA device is present and active
  4. Inspect registered memory regions
    Use 'rdma mr list' or check '/sys/class/infiniband/*/mr/' to list registered memory regions, then examine their page sizes
    Affected if Any memory region is registered with a page_size that differs from the system PAGE_SIZE (typically 4096 bytes)
  5. Verify page size configuration
    Run 'getconf PAGE_SIZE' to determine system page size, then compare with page sizes used in RDMA memory regions
    Affected if Memory regions exist with mr->page_size != system PAGE_SIZE

The environment is affected if the kernel version falls within the affected ranges AND the rxe driver is loaded AND any RDMA memory regions are registered with page sizes that differ from system PAGE_SIZE.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.18.14 / 6.19.4 or later
Fixed in 6.18.146.19.4
Vendor patch git.kernel.org →
Interim mitigation

Apply the kernel patch that replaces xarray with a pre-allocated rxe_mr_page array and properly handles MR page size relationships with system PAGE_SIZE through offset tracking and boundary checks.

Recommended fix High confidence

Linux Kernel 6.18.14 or later, or Linux Kernel 6.19.4 or later

  1. Identify the currently running Linux kernel version using `uname -r`
  2. Determine which stable branch applies to your current version (6.2.3 to 6.18.x requires upgrade to 6.18.14 or later; 6.19.x requires upgrade to 6.19.4 or later)
  3. Apply the appropriate kernel upgrade via your distribution's package manager (e.g., `apt update && apt upgrade linux-image-*` for Debian/Ubuntu, `yum update kernel` for RHEL/CentOS, or `dnf upgrade kernel` for Fedora)
  4. Reboot the system to load the new kernel
  5. Verify the fix is applied by checking the kernel version matches or exceeds the fixed release (6.18.14 or 6.19.4)
  6. If using RDMA/rxe, verify the module loads correctly: `modprobe rxe_cfg status`
Caveat Kernel upgrades may require system reboot and could have compatibility implications with custom modules or specific hardware drivers; test in staging environment before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation3.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA3.0 h
24.0 hours of engineering $4,200
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-46325 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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