{"id":"CVE-2025-39784","state":"PUBLISHED","title":"PCI: Fix link speed calculation on retrain failure","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nPCI: Fix link speed calculation on retrain failure\n\nWhen pcie_failed_link_retrain() fails to retrain, it tries to revert to the\nprevious link speed.  However it calculates that speed from the Link\nControl 2 register without masking out non-speed bits first.\n\nPCIE_LNKCTL2_TLS2SPEED() converts such incorrect values to\nPCI_SPEED_UNKNOWN (0xff), which in turn causes a WARN splat in\npcie_set_target_speed():\n\n  pci 0000:00:01.1: [1022:14ed] type 01 class 0x060400 PCIe Root Port\n  pci 0000:00:01.1: broken device, retraining non-functional downstream link at 2.5GT/s\n  pci 0000:00:01.1: retraining failed\n  WARNING: CPU: 1 PID: 1 at drivers/pci/pcie/bwctrl.c:168 pcie_set_target_speed\n  RDX: 0000000000000001 RSI: 00000000000000ff RDI: ffff9acd82efa000\n  pcie_failed_link_retrain\n  pci_device_add\n  pci_scan_single_device\n\nMask out the non-speed bits in PCIE_LNKCTL2_TLS2SPEED() and\nPCIE_LNKCAP_SLS2SPEED() so they don't incorrectly return PCI_SPEED_UNKNOWN.\n\n[bhelgaas: commit log, add details from https://lore.kernel.org/r/1c92ef6bcb314ee6977839b46b393282e4f52e74.1750684771.git.lukas@wunner.de]","publishedAt":"2025-09-11T16:56:34.097Z","updatedAt":"2026-05-11T21:36:13.426Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"de9a6c8d5dbfedb5eb3722c822da0490f6a59a45","status":"affected","lessThan":"16557320f378262b5c605b15edebd3642406992a","versionType":"git"},{"version":"de9a6c8d5dbfedb5eb3722c822da0490f6a59a45","status":"affected","lessThan":"9989e0ca7462c62f93dbc62f684448aa2efb9226","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/pci/pci.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.16.4","status":"unaffected","lessThanOrEqual":"6.16.*","versionType":"semver"},{"version":"6.17","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/pci/pci.h"]}],"references":["https://git.kernel.org/stable/c/16557320f378262b5c605b15edebd3642406992a","https://git.kernel.org/stable/c/9989e0ca7462c62f93dbc62f684448aa2efb9226"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/39xxx/CVE-2025-39784.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-39784","state":"PUBLISHED","datePublished":"2025-09-11T16:56:34.097Z","dateUpdated":"2026-05-11T21:36:13.426Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T07:20:57.130Z"},"containers":{"cna":{"title":"PCI: Fix link speed calculation on retrain failure","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nPCI: Fix link speed calculation on retrain failure\n\nWhen pcie_failed_link_retrain() fails to retrain, it tries to revert to the\nprevious link speed.  However it calculates that speed from the Link\nControl 2 register without masking out non-speed bits first.\n\nPCIE_LNKCTL2_TLS2SPEED() converts such incorrect values to\nPCI_SPEED_UNKNOWN (0xff), which in turn causes a WARN splat in\npcie_set_target_speed():\n\n  pci 0000:00:01.1: [1022:14ed] type 01 class 0x060400 PCIe Root Port\n  pci 0000:00:01.1: broken device, retraining non-functional downstream link at 2.5GT/s\n  pci 0000:00:01.1: retraining failed\n  WARNING: CPU: 1 PID: 1 at drivers/pci/pcie/bwctrl.c:168 pcie_set_target_speed\n  RDX: 0000000000000001 RSI: 00000000000000ff RDI: ffff9acd82efa000\n  pcie_failed_link_retrain\n  pci_device_add\n  pci_scan_single_device\n\nMask out the non-speed bits in PCIE_LNKCTL2_TLS2SPEED() and\nPCIE_LNKCAP_SLS2SPEED() so they don't incorrectly return PCI_SPEED_UNKNOWN.\n\n[bhelgaas: commit log, add details from https://lore.kernel.org/r/1c92ef6bcb314ee6977839b46b393282e4f52e74.1750684771.git.lukas@wunner.de]"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"de9a6c8d5dbfedb5eb3722c822da0490f6a59a45","status":"affected","lessThan":"16557320f378262b5c605b15edebd3642406992a","versionType":"git"},{"version":"de9a6c8d5dbfedb5eb3722c822da0490f6a59a45","status":"affected","lessThan":"9989e0ca7462c62f93dbc62f684448aa2efb9226","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/pci/pci.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.16.4","status":"unaffected","lessThanOrEqual":"6.16.*","versionType":"semver"},{"version":"6.17","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/pci/pci.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/16557320f378262b5c605b15edebd3642406992a"},{"url":"https://git.kernel.org/stable/c/9989e0ca7462c62f93dbc62f684448aa2efb9226"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T21:36:13.426Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.16.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.17"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}