In the Linux kernel, the following vulnerability has been resolved:
PCI: Fix link speed calculation on retrain failure
When pcie_failed_link_retrain() fails to retrain, it tries to revert to the
previous link speed. However it calculates that speed from the Link
Control 2 register without masking out non-speed bits first.
PCIE_LNKCTL2_TLS2SPEED() converts such incorrect values to
PCI_SPEED_UNKNOWN (0xff), which in turn causes a WARN splat in
pcie_set_target_speed():
pci 0000:00:01.1: [1022:14ed] type 01 class 0x060400 PCIe Root Port
pci 0000:00:01.1: broken device, retraining non-functional downstream link at 2.5GT/s
pci 0000:00:01.1: retraining failed
WARNING: CPU: 1 PID: 1 at drivers/pci/pcie/bwctrl.c:168 pcie_set_target_speed
RDX: 0000000000000001 RSI: 00000000000000ff RDI: ffff9acd82efa000
pcie_failed_link_retrain
pci_device_add
pci_scan_single_device
Mask out the non-speed bits in PCIE_LNKCTL2_TLS2SPEED() and
PCIE_LNKCAP_SLS2SPEED() so they don't incorrectly return PCI_SPEED_UNKNOWN.
[bhelgaas: commit log, add details from https://lore.kernel.org/r/1c92ef6bcb314ee6977839b46b393282e4f52e74.1750684771.git.lukas@wunner.de]
PCI: Fix link speed calculation on retrain failure
When pcie_failed_link_retrain() fails to retrain, it tries to revert to the
previous link speed. However it calculates that speed from the Link
Control 2 register without masking out non-speed bits first.
PCIE_LNKCTL2_TLS2SPEED() converts such incorrect values to
PCI_SPEED_UNKNOWN (0xff), which in turn causes a WARN splat in
pcie_set_target_speed():
pci 0000:00:01.1: [1022:14ed] type 01 class 0x060400 PCIe Root Port
pci 0000:00:01.1: broken device, retraining non-functional downstream link at 2.5GT/s
pci 0000:00:01.1: retraining failed
WARNING: CPU: 1 PID: 1 at drivers/pci/pcie/bwctrl.c:168 pcie_set_target_speed
RDX: 0000000000000001 RSI: 00000000000000ff RDI: ffff9acd82efa000
pcie_failed_link_retrain
pci_device_add
pci_scan_single_device
Mask out the non-speed bits in PCIE_LNKCTL2_TLS2SPEED() and
PCIE_LNKCAP_SLS2SPEED() so they don't incorrectly return PCI_SPEED_UNKNOWN.
[bhelgaas: commit log, add details from https://lore.kernel.org/r/1c92ef6bcb314ee6977839b46b393282e4f52e74.1750684771.git.lukas@wunner.de]
Metrics
Affected Vendors & Products
No data.
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 11 Sep 2025 17:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: PCI: Fix link speed calculation on retrain failure When pcie_failed_link_retrain() fails to retrain, it tries to revert to the previous link speed. However it calculates that speed from the Link Control 2 register without masking out non-speed bits first. PCIE_LNKCTL2_TLS2SPEED() converts such incorrect values to PCI_SPEED_UNKNOWN (0xff), which in turn causes a WARN splat in pcie_set_target_speed(): pci 0000:00:01.1: [1022:14ed] type 01 class 0x060400 PCIe Root Port pci 0000:00:01.1: broken device, retraining non-functional downstream link at 2.5GT/s pci 0000:00:01.1: retraining failed WARNING: CPU: 1 PID: 1 at drivers/pci/pcie/bwctrl.c:168 pcie_set_target_speed RDX: 0000000000000001 RSI: 00000000000000ff RDI: ffff9acd82efa000 pcie_failed_link_retrain pci_device_add pci_scan_single_device Mask out the non-speed bits in PCIE_LNKCTL2_TLS2SPEED() and PCIE_LNKCAP_SLS2SPEED() so they don't incorrectly return PCI_SPEED_UNKNOWN. [bhelgaas: commit log, add details from https://lore.kernel.org/r/1c92ef6bcb314ee6977839b46b393282e4f52e74.1750684771.git.lukas@wunner.de] | |
| Title | PCI: Fix link speed calculation on retrain failure | |
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-09-11T16:56:34.097Z
Reserved: 2025-04-16T07:20:57.130Z
Link: CVE-2025-39784
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-09-11T17:15:44.493
Modified: 2025-09-11T17:15:44.493
Link: CVE-2025-39784
Redhat
No data.
OpenCVE Enrichment
No data.