CVEvulnerability
CVE-2026-98020
- Status
- Received
- Published
- 2026-09-25
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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.
References
- https://git.kernel.org/stable/c/09f831bfe39de5b8026fefb3d106b5cc93272170 git.kernel.org
- https://git.kernel.org/stable/c/0bf9f3bae3c4b1eadb7a2bf63350333db7dac0d9 git.kernel.org
- https://git.kernel.org/stable/c/2cc697565fd19b5ba2d100cdd4a20dd6d263abc2 git.kernel.org
- https://git.kernel.org/stable/c/7980325b2f71e3f65c1323c39792e2455da6fab6 git.kernel.org
- https://git.kernel.org/stable/c/fa31bd14c5042c6315bb2182c963f03ca6e79ca4 git.kernel.org