CVEvulnerability
CVE-2026-93264
- Status
- Received
- Published
- 2026-09-24
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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.
References
- https://git.kernel.org/stable/c/1d4b5902773475fc97151379b7e5f09cad0fa57b git.kernel.org
- https://git.kernel.org/stable/c/229b42d7450c1cf96f45ec39ebb69211b06bc036 git.kernel.org
- https://git.kernel.org/stable/c/3982714e15512b83115897806dacc94899683420 git.kernel.org
- https://git.kernel.org/stable/c/489b28f2377afa70c18c45b06a6387f3d39bb123 git.kernel.org
- https://git.kernel.org/stable/c/665cd418b8561a099c3854443f8ad8ae751b72a0 git.kernel.org
- https://git.kernel.org/stable/c/932e5684906a090644a9061fae2d254041c3b8f2 git.kernel.org
- https://git.kernel.org/stable/c/aadf3f9b5edb7f0a77e9172b237d2e07c754829c git.kernel.org
- https://git.kernel.org/stable/c/da7805f0211af19968584e621074f253ac07dba7 git.kernel.org