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]
References
Configurations
History
25 Nov 2025, 18:49
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| First Time |
Linux linux Kernel
Linux |
|
| CWE | NVD-CWE-noinfo | |
| References | () https://git.kernel.org/stable/c/16557320f378262b5c605b15edebd3642406992a - Patch | |
| References | () https://git.kernel.org/stable/c/9989e0ca7462c62f93dbc62f684448aa2efb9226 - Patch | |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
Information
Published : 2025-09-11 17:15
Updated : 2025-11-25 18:49
NVD link : CVE-2025-39784
Mitre link : CVE-2025-39784
CVE.ORG link : CVE-2025-39784
JSON object : View
Products Affected
linux
- linux_kernel
CWE