Linux KernelOperating system · Linux

CVE-2024-35814

HIGH · 8.8 CVSS v3.1 Published 2024-05-17
Fix available
A fix is available. Upgrade to 6.6.24 / 6.7.12 or later.
See remediation →
90/100
Remediation priority · Urgent
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: swiotlb: Fix double-allocation of slots due to broken alignment handling Commit bbb73a103fbb ("swiotlb: fix a braino in the alignment check fix"), which was a fix for commit 0eee5ae10256 ("swiotlb: fix slot alignment checks"), causes a functional regression with vsock in a virtual machine using bouncing via a restricted DMA SWIOTLB pool. When virtio allocates the virtqueues for the vsock device using dma_alloc_coherent(), the SWIOTLB search can return page-unaligned allocations if 'area->index' was left unaligned by a previous allocation from the buffer: # Final address in brackets is the SWIOTLB address returned to the caller | virtio-pci 0000:00:07.0: orig_addr 0x0 alloc_size 0x2000, iotlb_align_mask 0x800 stride 0x2: got slot 1645-1649/7168 (0x98326800) | virtio-pci 0000:00:07.0: orig_addr 0x0 alloc_size 0x2000, iotlb_align_mask 0x800 stride 0x2: got slot 1649-1653/7168 (0x98328800) | virtio-pci 0000:00:07.0: orig_addr 0x0 alloc_size 0x2000, iotlb_align_mask 0x800 stride 0x2: got slot 1653-1657/7168 (0x9832a800) This ends badly (typically buffer corruption and/or a hang) because swiotlb_alloc() is expecting a page-aligned allocation and so blindly returns a pointer to the 'struct page' corresponding to the allocation, therefore double-allocating the first half (2KiB slot) of the 4KiB page. Fix the problem by treating the allocation alignment separately to any additional alignment requirements from the device, using the maximum of the two as the stride to search the buffer slots and taking care to ensure a minimum of page-alignment for buffers larger than a page. This also resolves swiotlb allocation failures occuring due to the inclusion of ~PAGE_MASK in 'iotlb_align_mask' for large allocations and resulting in alignment requirements exceeding swiotlb_max_mapping_size().

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
How this class of weakness works · CWE-415

The same block of memory is freed twice, corrupting the allocator's bookkeeping in ways an attacker can shape toward code execution. It usually stems from tangled ownership of a pointer. The fix is clear, single ownership of each allocation and clearing pointers once they are freed.

General guidance for the double free class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

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:>= 6.3, < 6.6.24>= 6.7, < 6.7.12>= 6.8, < 6.8.3

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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

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 6.6.24 / 6.7.12 / 6.8.3 or later
Fixed in 6.6.246.7.126.8.3
Vendor patch git.kernel.org →
Recommended fix High confidence

Upgrade to kernel 6.6.24+, 6.7.12+, or 6.8.3+ (or the latest stable release in your respective kernel branch)

  1. 1. Identify the currently running kernel version using `uname -r`
  2. 2. Check if the current version is within the affected range: >= 6.3 and < 6.6.24, or >= 6.7 and < 6.7.12, or >= 6.8 and < 6.8.3
  3. 3. If affected, upgrade the Linux kernel to a fixed version using your distribution's package manager (e.g., `apt update && apt upgrade` for Debian/Ubuntu, `yum update` for RHEL/CentOS, or `dnf upgrade` for Fedora)
  4. 4. After upgrade, reboot the system to load the fixed kernel: `sudo reboot`
  5. 5. Verify the fix is applied by checking the kernel version after reboot with `uname -r` - ensure it is 6.6.24+, 6.7.12+, or 6.8.3+ respectively
  6. 6. Alternatively, manually apply the fix by cherry-picking commit 04867a7a33324c9c562ee7949dbcaab7aaad1fb4 and rebuilding the kernel (not recommended for production systems)
Caveat Standard kernel upgrade risks apply - ensure compatibility with hardware drivers and dependent modules before rebooting

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

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,950. Get the upgrade done

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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-2024-35814 in production — separate from our analysis above.

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