CVE-2026-93264
RDMA/efa: Fix PBL chunk length computation
Description
In the Linux kernel, the following vulnerability has been resolved: RDMA/efa: Fix PBL chunk length computation On register MR, when creating the PBL, if it's an indirect PBL we create a chunk list to hold the PBL pages pointers. Each chunk is 4KB in size and can hold 510 addresses (EFA_PTRS_PER_CHUNK) and has a 12-byte control buffer at the end of it holding the next chunk's pointer and its length. If the PBL number of pages is a multiple of EFA_PTRS_PER_CHUNK, the calculated last chunk length is wrongly computed as 0, even though that chunk is fully populated with 510 real page pointers. This wrong length is used both to DMA map the chunk and is propagated to the device, causing the device to see the chunk as empty and reject the memory registration. Fix the calculation so it will be performed only if the number of pages isn't a multiple of EFA_PTRS_PER_CHUNK, if it is, its already handled in the above loop correctly. Also prevent out-of-bounds reach in the chunks array in such scenario.
INFO
Published Date :
Sept. 24, 2026, 4:17 p.m.
Last Modified :
Sept. 24, 2026, 4:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to include the PBL chunk length fix.
- Ensure PBL page calculations are handled correctly.
- Prevent out-of-bounds access in the chunks array.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 24, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: RDMA/efa: Fix PBL chunk length computation On register MR, when creating the PBL, if it's an indirect PBL we create a chunk list to hold the PBL pages pointers. Each chunk is 4KB in size and can hold 510 addresses (EFA_PTRS_PER_CHUNK) and has a 12-byte control buffer at the end of it holding the next chunk's pointer and its length. If the PBL number of pages is a multiple of EFA_PTRS_PER_CHUNK, the calculated last chunk length is wrongly computed as 0, even though that chunk is fully populated with 510 real page pointers. This wrong length is used both to DMA map the chunk and is propagated to the device, causing the device to see the chunk as empty and reject the memory registration. Fix the calculation so it will be performed only if the number of pages isn't a multiple of EFA_PTRS_PER_CHUNK, if it is, its already handled in the above loop correctly. Also prevent out-of-bounds reach in the chunks array in such scenario. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/93xxx/CVE-2026-93264.json">CVE-2026-93264</a> Added Reference https://git.kernel.org/stable/c/1d4b5902773475fc97151379b7e5f09cad0fa57b Added Reference https://git.kernel.org/stable/c/229b42d7450c1cf96f45ec39ebb69211b06bc036 Added Reference https://git.kernel.org/stable/c/3982714e15512b83115897806dacc94899683420 Added Reference https://git.kernel.org/stable/c/489b28f2377afa70c18c45b06a6387f3d39bb123 Added Reference https://git.kernel.org/stable/c/665cd418b8561a099c3854443f8ad8ae751b72a0 Added Reference https://git.kernel.org/stable/c/932e5684906a090644a9061fae2d254041c3b8f2 Added Reference https://git.kernel.org/stable/c/aadf3f9b5edb7f0a77e9172b237d2e07c754829c Added Reference https://git.kernel.org/stable/c/da7805f0211af19968584e621074f253ac07dba7