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.
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.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 24 Sep 2026 16:00:00 +0000
| Type | Values Removed | Values 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. | |
| Title | RDMA/efa: Fix PBL chunk length computation | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-24T15:52:03.741Z
Reserved: 2026-09-17T16:02:15.097Z
Link: CVE-2026-93264
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-24T16:17:23.193
Modified: 2026-09-24T16:17:23.193
Link: CVE-2026-93264
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.