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.
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.
Published:
2026-09-25
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
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References
History
Fri, 25 Sep 2026 10:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | pds_core: fix cmd_regs access racing BAR unmap on reset | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-25T10:23:40.900Z
Reserved: 2026-09-25T10:19:56.069Z
Link: CVE-2026-98020
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-25T11:17:30.480
Modified: 2026-09-25T11:17:30.480
Link: CVE-2026-98020
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.