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UBUNTU-CVE-2025-22022 High

UBUNTU-CVE-2025-22022

In the Linux kernel, the following vulnerability has been resolved: usb: xhci: Apply the link chain quirk on NEC isoc endpoints Two clearly different specimens of NEC uPD720200 (one with start/stop bug, one without) were seen to cause IOMMU faults after some Missed Service Errors. Faulting address is immediately after a transfer ring segment and patched dynamic debug messages revealed that the MSE was received when waiting for a TD near the end of that segment: [ 1.041954] xhci_hcd: Miss service interval error for slot 1 ep 2 expected TD DMA ffa08fe0 [ 1.042120] xhci_hcd: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0005 address=0xffa09000 flags=0x0000] [ 1.042146] xhci_hcd: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0005 address=0xffa09040 flags=0x0000] It gets even funnier if the next page is a ring segment accessible to the HC. Below, it reports MSE in segment at ff1e8000, plows through a zero-filled page at ff1e9000 and starts reporting events for TRBs in page at ff1ea000 every microframe, instead of jumping to seg ff1e6000. [ 7.041671] xhci_hcd: Miss service interval error for slot 1 ep 2 expected TD DMA ff1e8fe0 [ 7.041999] xhci_hcd: Miss service interval error for slot 1 ep 2 expected TD DMA ff1e8fe0 [ 7.042011] xhci_hcd: WARN: buffer overrun event for slot 1 ep 2 on endpoint [ 7.042028] xhci_hcd: All TDs skipped for slot 1 ep 2. Clear skip flag. [ 7.042134] xhci_hcd: WARN: buffer overrun event for slot 1 ep 2 on endpoint [ 7.042138] xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 31 [ 7.042144] xhci_hcd: Looking for event-dma 00000000ff1ea040 trb-start 00000000ff1e6820 trb-end 00000000ff1e6820 [ 7.042259] xhci_hcd: WARN: buffer overrun event for slot 1 ep 2 on endpoint [ 7.042262] xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 31 [ 7.042266] xhci_hcd: Looking for event-dma 00000000ff1ea050 trb-start 00000000ff1e6820 trb-end 00000000ff1e6820 At some point completion events change from Isoch Buffer Overrun to Short Packet and the HC finally finds cycle bit mismatch in ff1ec000. [ 7.098130] xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 13 [ 7.098132] xhci_hcd: Looking for event-dma 00000000ff1ecc50 trb-start 00000000ff1e6820 trb-end 00000000ff1e6820 [ 7.098254] xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 13 [ 7.098256] xhci_hcd: Looking for event-dma 00000000ff1ecc60 trb-start 00000000ff1e6820 trb-end 00000000ff1e6820 [ 7.098379] xhci_hcd: Overrun event on slot 1 ep 2 It's possible that data from the isochronous device were written to random buffers of pending TDs on other endpoints (either IN or OUT), other devices or even other HCs in the same IOMMU domain. Lastly, an error from a different USB device on another HC. Was it caused by the above? I don't know, but it may have been. The disk was working without any other issues and generated PCIe traffic to starve the NEC of upstream BW and trigger those MSEs. The two HCs shared one x1 slot by means of a commercial "PCIe splitter" board. [ 7.162604] usb 10-2: reset SuperSpeed USB device number 3 using xhci_hcd [ 7.178990] sd 9:0:0:0: [sdb] tag#0 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=DRIVER_OK cmd_age=0s [ 7.179001] sd 9:0:0:0: [sdb] tag#0 CDB: opcode=0x28 28 00 04 02 ae 00 00 02 00 00 [ 7.179004] I/O error, dev sdb, sector 67284480 op 0x0:(READ) flags 0x80700 phys_seg 5 prio class 0 Fortunately, it appears that this ridiculous bug is avoided by setting the chain bit of Link TRBs on isochronous rings. Other ancient HCs are known which also expect the bit to be set and they ignore Link TRBs if it's not. Reportedly, 0.95 spec guaranteed that the bit is set. The bandwidth-starved NEC HC running a 32KB/uframe UVC endpoint reports tens of MSEs per second and runs into the bug within seconds. Chaining Link TRBs allows the same workload to run for many minutes, many times. No ne ---truncated---

Exploit probability Not scored
Published April 16, 2025
Required by Not available
Last source change August 19, 2026

02 / AFFECTED SOFTWARE

Affected packages

Ubuntu:22.04:LTS linux-starfive-6.5

11 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-iot

53 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-azure

116 explicit affected versions

Ubuntu:22.04:LTS linux-ibm

80 explicit affected versions

Ubuntu:18.04:LTS linux-oem

50 explicit affected versions

Ubuntu:18.04:LTS linux-aws-5.0

6 explicit affected versions

Ubuntu:20.04:LTS linux-aws-5.11

12 explicit affected versions

Ubuntu:22.04:LTS linux-oem-6.5

19 explicit affected versions

Ubuntu:20.04:LTS linux-raspi2

6 explicit affected versions

Ubuntu:22.04:LTS linux

90 explicit affected versions

Ubuntu:24.04:LTS linux-riscv

24 explicit affected versions

Ubuntu:22.04:LTS linux-gkeop

75 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-lowlatency-hwe-5.15

75 explicit affected versions

Ubuntu:Pro:FIPS-updates:20.04:LTS linux-fips

91 explicit affected versions

Ubuntu:22.04:LTS linux-azure

79 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-gcp-5.15

70 explicit affected versions

Ubuntu:22.04:LTS linux-riscv-6.5

10 explicit affected versions

Ubuntu:22.04:LTS linux-ibm-6.8

32 explicit affected versions

Ubuntu:24.04:LTS linux-oem-6.8

26 explicit affected versions

Ubuntu:22.04:LTS linux-gke

82 explicit affected versions

Ubuntu:Pro:14.04:LTS linux

191 explicit affected versions

Ubuntu:22.04:LTS linux-azure-5.19

7 explicit affected versions

Ubuntu:22.04:LTS linux-raspi

77 explicit affected versions

Ubuntu:22.04:LTS linux-oracle-6.8

35 explicit affected versions

Ubuntu:22.04:LTS linux-gcp-6.5

13 explicit affected versions

Ubuntu:Pro:FIPS-updates:18.04:LTS linux-azure-fips

85 explicit affected versions

Ubuntu:24.04:LTS linux-nvidia

39 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.14

35 explicit affected versions

Ubuntu:Pro:FIPS-updates:22.04:LTS linux-gcp-fips

42 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia-tegra

40 explicit affected versions

Ubuntu:20.04:LTS linux-gke-5.15

18 explicit affected versions

Ubuntu:Pro:FIPS-updates:22.04:LTS linux-azure-fips

35 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-oracle

118 explicit affected versions

Ubuntu:22.04:LTS linux-azure-fde

64 explicit affected versions

Ubuntu:24.04:LTS linux-oracle

40 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-hwe-5.4

120 explicit affected versions

Ubuntu:20.04:LTS linux-aws-5.13

13 explicit affected versions

Ubuntu:20.04:LTS linux-aws-5.8

4 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-kvm

121 explicit affected versions

Ubuntu:16.04:LTS linux-hwe-edge

23 explicit affected versions

Ubuntu:24.04:LTS linux

47 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-gcp

124 explicit affected versions

Ubuntu:Pro:FIPS:18.04:LTS linux-gcp-fips

1 explicit affected versions

Ubuntu:24.04:LTS linux-raspi-realtime

1 explicit affected versions

Ubuntu:20.04:LTS linux-hwe-5.8

21 explicit affected versions

Ubuntu:22.04:LTS linux-azure-fde-6.8

9 explicit affected versions

Ubuntu:20.04:LTS linux-hwe-5.13

16 explicit affected versions

Ubuntu:22.04:LTS linux-lowlatency-hwe-6.2

10 explicit affected versions

Ubuntu:Pro:FIPS-updates:20.04:LTS linux-aws-fips

76 explicit affected versions

Ubuntu:24.04:LTS linux-aws

43 explicit affected versions

Ubuntu:24.04:LTS linux-hwe-6.11

6 explicit affected versions

Ubuntu:18.04:LTS linux-oracle-5.0

7 explicit affected versions

Ubuntu:20.04:LTS linux-riscv

12 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-oracle

111 explicit affected versions

Ubuntu:24.04:LTS linux-azure-6.11

6 explicit affected versions

Ubuntu:20.04:LTS linux-gcp-5.11

12 explicit affected versions

Ubuntu:22.04:LTS linux-azure-6.5

14 explicit affected versions

Ubuntu:25.10 linux-azure-fde

10 explicit affected versions

Ubuntu:22.04:LTS linux-intel-iot-realtime

1 explicit affected versions

Ubuntu:20.04:LTS linux-intel-5.13

7 explicit affected versions

Ubuntu:24.04:LTS linux-nvidia-tegra

11 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-azure-5.4

104 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.13

12 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-raspi

105 explicit affected versions

Ubuntu:20.04:LTS linux-oracle-5.11

12 explicit affected versions

Ubuntu:Pro:Realtime:22.04:LTS linux-realtime-6.8

36 explicit affected versions

Ubuntu:Pro:14.04:LTS linux-aws

120 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia-tegra-igx

36 explicit affected versions

Ubuntu:22.04:LTS linux-azure-6.8

25 explicit affected versions

Ubuntu:24.04:LTS linux-gkeop

29 explicit affected versions

Ubuntu:18.04:LTS linux-hwe-edge

10 explicit affected versions

Ubuntu:18.04:LTS linux-gke-5.4

37 explicit affected versions

Ubuntu:24.04:LTS linux-azure-nvidia

10 explicit affected versions

Ubuntu:22.04:LTS linux-oracle-6.5

13 explicit affected versions

Ubuntu:22.04:LTS linux-lowlatency-hwe-6.8

35 explicit affected versions

Ubuntu:22.04:LTS linux-azure-fde-6.2

10 explicit affected versions

Ubuntu:Pro:Realtime:22.04:LTS linux-intel-iot-realtime

57 explicit affected versions

Ubuntu:Pro:FIPS:20.04:LTS linux-aws-fips

1 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.10

26 explicit affected versions

Ubuntu:Pro:FIPS-updates:24.04:LTS linux-azure-fips

6 explicit affected versions

Ubuntu:20.04:LTS linux-gcp-5.13

13 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-aws

144 explicit affected versions

Ubuntu:22.04:LTS linux-xilinx-zynqmp

29 explicit affected versions

Ubuntu:Pro:FIPS:18.04:LTS linux-fips

1 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.6

29 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-gcp-5.4

111 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-5.3

13 explicit affected versions

Ubuntu:22.04:LTS linux-lowlatency

87 explicit affected versions

Ubuntu:24.04:LTS linux-nvidia-lowlatency

36 explicit affected versions

Ubuntu:22.04:LTS linux-gcp-6.8

36 explicit affected versions

Ubuntu:Pro:FIPS:18.04:LTS linux-azure-fips

1 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-raspi-5.4

100 explicit affected versions

Ubuntu:22.04:LTS linux-aws

82 explicit affected versions

Ubuntu:Pro:FIPS-updates:22.04:LTS linux-aws-fips

45 explicit affected versions

Ubuntu:18.04:LTS linux-gke-4.15

33 explicit affected versions

Ubuntu:22.04:LTS linux-riscv

23 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-ibm-5.15

51 explicit affected versions

Ubuntu:18.04:LTS linux-aws-5.3

10 explicit affected versions

Ubuntu:Pro:FIPS-updates:24.04:LTS linux-fips

15 explicit affected versions

Ubuntu:Pro:16.04:LTS linux

188 explicit affected versions

Ubuntu:Pro:FIPS-updates:24.04:LTS linux-gcp-fips

14 explicit affected versions

Ubuntu:Nvidia-BlueField:24.04:LTS linux-bluefield

11 explicit affected versions

Ubuntu:20.04:LTS linux-hwe-5.11

12 explicit affected versions

Ubuntu:20.04:LTS linux-azure-5.8

7 explicit affected versions

Ubuntu:22.04:LTS linux-gcp-6.2

12 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-gcp

138 explicit affected versions

Ubuntu:Pro:FIPS:16.04:LTS linux-fips

2 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia

67 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-kvm

132 explicit affected versions

Ubuntu:22.04:LTS linux-oracle

83 explicit affected versions

Ubuntu:Pro:14.04:LTS linux-lts-xenial

165 explicit affected versions

Ubuntu:Pro:18.04:LTS linux

154 explicit affected versions

Ubuntu:22.04:LTS linux-lowlatency-hwe-5.19

10 explicit affected versions

Ubuntu:22.04:LTS linux-oem-5.17

26 explicit affected versions

Ubuntu:24.04:LTS linux-azure

34 explicit affected versions

Ubuntu:Pro:FIPS-preview:22.04:LTS linux-azure-fips

1 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-intel-iotg-5.15

59 explicit affected versions

Ubuntu:22.04:LTS linux-hwe-6.8

30 explicit affected versions

Ubuntu:24.04:LTS linux-raspi

42 explicit affected versions

Ubuntu:22.04:LTS linux-azure-6.2

13 explicit affected versions

Ubuntu:24.04:LTS linux-ibm

41 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-aws

139 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-ibm-5.4

78 explicit affected versions

Ubuntu:22.04:LTS linux-oem-6.0

16 explicit affected versions

Ubuntu:22.04:LTS linux-kvm

81 explicit affected versions

Ubuntu:24.04:LTS linux-gcp

45 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-aws-hwe

116 explicit affected versions

Ubuntu:22.04:LTS linux-azure-fde-5.19

3 explicit affected versions

Ubuntu:Pro:20.04:LTS linux

132 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-gcp-4.15

93 explicit affected versions

Ubuntu:Pro:FIPS:20.04:LTS linux-azure-fips

1 explicit affected versions

Ubuntu:24.04:LTS linux-gcp-6.11

5 explicit affected versions

Ubuntu:Pro:FIPS-preview:22.04:LTS linux-aws-fips

2 explicit affected versions

Ubuntu:20.04:LTS linux-gke

51 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-azure-4.15

92 explicit affected versions

Ubuntu:24.04:LTS linux-oem-6.11

15 explicit affected versions

Ubuntu:Pro:Realtime:24.04:LTS linux-raspi-realtime

37 explicit affected versions

Ubuntu:20.04:LTS linux-azure-5.13

12 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-azure-5.15

66 explicit affected versions

Ubuntu:22.04:LTS linux-intel-iotg

70 explicit affected versions

Ubuntu:22.04:LTS linux-oem-6.1

27 explicit affected versions

Ubuntu:Nvidia-BlueField:22.04:LTS linux-bluefield

56 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-oracle

121 explicit affected versions

Ubuntu:Pro:FIPS:18.04:LTS linux-aws-fips

1 explicit affected versions

Ubuntu:Pro:FIPS:20.04:LTS linux-fips

1 explicit affected versions

Ubuntu:Pro:FIPS-updates:18.04:LTS linux-fips

98 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia-6.8

38 explicit affected versions

Ubuntu:22.04:LTS linux-gcp-5.19

8 explicit affected versions

Ubuntu:Pro:FIPS-updates:22.04:LTS linux-fips

47 explicit affected versions

Ubuntu:20.04:LTS linux-oracle-5.8

5 explicit affected versions

Ubuntu:24.04:LTS linux-intel

3 explicit affected versions

Ubuntu:22.04:LTS linux-riscv-5.19

8 explicit affected versions

Ubuntu:Pro:FIPS:20.04:LTS linux-gcp-fips

1 explicit affected versions

Ubuntu:22.04:LTS linux-hwe-6.2

10 explicit affected versions

Ubuntu:24.04:LTS linux-lowlatency-hwe-6.11

5 explicit affected versions

Ubuntu:Pro:Realtime:24.04:LTS linux-realtime

41 explicit affected versions

Ubuntu:22.04:LTS linux-lowlatency-hwe-6.5

13 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-oracle-5.4

110 explicit affected versions

Ubuntu:20.04:LTS linux-azure-5.11

13 explicit affected versions

Ubuntu:Pro:FIPS-updates:20.04:LTS linux-azure-fips

72 explicit affected versions

Ubuntu:22.04:LTS linux-starfive-5.19

7 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-azure

140 explicit affected versions

Ubuntu:24.04:LTS linux-nvidia-6.11

5 explicit affected versions

Ubuntu:Pro:FIPS-updates:18.04:LTS linux-aws-fips

94 explicit affected versions

Ubuntu:20.04:LTS linux-riscv-5.8

10 explicit affected versions

Ubuntu:20.04:LTS linux-oracle-5.13

12 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-nvidia-tegra-5.15

30 explicit affected versions

Ubuntu:Pro:18.04:LTS linux-aws-5.4

108 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-bluefield

80 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-xilinx-zynqmp

56 explicit affected versions

Ubuntu:18.04:LTS linux-azure

44 explicit affected versions

Ubuntu:18.04:LTS linux-azure-5.3

16 explicit affected versions

Ubuntu:22.04:LTS linux-starfive-6.2

3 explicit affected versions

Ubuntu:20.04:LTS linux-riscv-5.11

13 explicit affected versions

Ubuntu:20.04:LTS linux-azure-fde

26 explicit affected versions

Ubuntu:20.04:LTS linux-gkeop-5.15

45 explicit affected versions

Ubuntu:18.04:LTS linux-gkeop-5.4

37 explicit affected versions

Ubuntu:24.04:LTS linux-lowlatency

46 explicit affected versions

Ubuntu:22.04:LTS linux-aws-6.5

14 explicit affected versions

Ubuntu:18.04:LTS linux-gcp

38 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-hwe

167 explicit affected versions

Ubuntu:18.04:LTS linux-oracle-5.3

9 explicit affected versions

Ubuntu:22.04:LTS linux-hwe-5.19

11 explicit affected versions

Ubuntu:22.04:LTS linux-riscv-6.8

34 explicit affected versions

Ubuntu:24.04:LTS linux-xilinx

15 explicit affected versions

Ubuntu:22.04:LTS linux-gcp

83 explicit affected versions

Ubuntu:24.04:LTS linux-azure-fde

8 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia-6.2

7 explicit affected versions

Ubuntu:Pro:FIPS:16.04:LTS linux-fips

97 explicit affected versions

Ubuntu:Pro:14.04:LTS linux-azure

121 explicit affected versions

Ubuntu:20.04:LTS linux-gcp-5.8

4 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-riscv-5.15

72 explicit affected versions

Ubuntu:24.04:LTS linux-realtime

1 explicit affected versions

Ubuntu:Pro:FIPS-preview:22.04:LTS linux-fips

1 explicit affected versions

Ubuntu:Pro:FIPS-preview:22.04:LTS linux-gcp-fips

1 explicit affected versions

Ubuntu:Pro:Realtime:22.04:LTS linux-realtime

81 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-hwe-5.15

72 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-aws-5.15

71 explicit affected versions

Ubuntu:22.04:LTS linux-hwe-6.5

13 explicit affected versions

Ubuntu:18.04:LTS linux-hwe

43 explicit affected versions

Ubuntu:Pro:FIPS-updates:20.04:LTS linux-gcp-fips

77 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-kvm

119 explicit affected versions

Ubuntu:22.04:LTS linux-aws-5.19

10 explicit affected versions

Ubuntu:22.04:LTS linux-allwinner-5.19

8 explicit affected versions

Ubuntu:24.04:LTS linux-gke

40 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-ibm

88 explicit affected versions

Ubuntu:22.04:LTS linux-aws-6.2

14 explicit affected versions

Ubuntu:18.04:LTS linux-azure-edge

4 explicit affected versions

Ubuntu:20.04:LTS linux-gkeop

78 explicit affected versions

Ubuntu:22.04:LTS linux-nvidia-6.5

11 explicit affected versions

Ubuntu:22.04:LTS linux-realtime

1 explicit affected versions

Ubuntu:Pro:FIPS-updates:18.04:LTS linux-gcp-fips

69 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-aws

123 explicit affected versions

Ubuntu:Pro:FIPS-updates:24.04:LTS linux-aws-fips

14 explicit affected versions

Ubuntu:22.04:LTS linux-aws-6.8

34 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-oracle-5.15

71 explicit affected versions

03 / CONNECTIONS

Connected vulnerabilities

04 / EVIDENCE

Source records

Open Source Vulnerabilities UBUNTU-CVE-2025-22022

In the Linux kernel, the following vulnerability has been resolved: usb: xhci: Apply the link chain quirk on NEC isoc endpoints Two clearly different specimens of NEC uPD720200 (one with start/stop bug, one without) were seen to cause IOMMU faults after some Missed Service Errors. Faulting address is immediately after a transfer ring segment and patched dynamic debug messages revealed that the MSE was received when waiting for a TD near the end of that segment: [ 1.041954] xhci_hcd: Miss service interval error for slot 1 ep 2 expected TD DMA ffa08fe0 [ 1.042120] xhci_hcd: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0005 address=0xffa09000 flags=0x0000] [ 1.042146] xhci_hcd: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0005 address=0xffa09040 flags=0x0000] It gets even funnier if the next page is a ring segment accessible to the HC. Below, it reports MSE in segment at ff1e8000, plows through a zero-filled page at ff1e9000 and starts reporting events for TRBs in page at ff1ea000 every microframe, instead of jumping to seg ff1e6000. [ 7.041671] xhci_hcd: Miss service interval error for slot 1 ep 2 expected TD DMA ff1e8fe0 [ 7.041999] xhci_hcd: Miss service interval error for slot 1 ep 2 expected TD DMA ff1e8fe0 [ 7.042011] xhci_hcd: WARN: buffer overrun event for slot 1 ep 2 on endpoint [ 7.042028] xhci_hcd: All TDs skipped for slot 1 ep 2. Clear skip flag. [ 7.042134] xhci_hcd: WARN: buffer overrun event for slot 1 ep 2 on endpoint [ 7.042138] xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 31 [ 7.042144] xhci_hcd: Looking for event-dma 00000000ff1ea040 trb-start 00000000ff1e6820 trb-end 00000000ff1e6820 [ 7.042259] xhci_hcd: WARN: buffer overrun event for slot 1 ep 2 on endpoint [ 7.042262] xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 31 [ 7.042266] xhci_hcd: Looking for event-dma 00000000ff1ea050 trb-start 00000000ff1e6820 trb-end 00000000ff1e6820 At some point completion events change from Isoch Buffer Overrun to Short Packet and the HC finally finds cycle bit mismatch in ff1ec000. [ 7.098130] xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 13 [ 7.098132] xhci_hcd: Looking for event-dma 00000000ff1ecc50 trb-start 00000000ff1e6820 trb-end 00000000ff1e6820 [ 7.098254] xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 13 [ 7.098256] xhci_hcd: Looking for event-dma 00000000ff1ecc60 trb-start 00000000ff1e6820 trb-end 00000000ff1e6820 [ 7.098379] xhci_hcd: Overrun event on slot 1 ep 2 It's possible that data from the isochronous device were written to random buffers of pending TDs on other endpoints (either IN or OUT), other devices or even other HCs in the same IOMMU domain. Lastly, an error from a different USB device on another HC. Was it caused by the above? I don't know, but it may have been. The disk was working without any other issues and generated PCIe traffic to starve the NEC of upstream BW and trigger those MSEs. The two HCs shared one x1 slot by means of a commercial "PCIe splitter" board. [ 7.162604] usb 10-2: reset SuperSpeed USB device number 3 using xhci_hcd [ 7.178990] sd 9:0:0:0: [sdb] tag#0 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=DRIVER_OK cmd_age=0s [ 7.179001] sd 9:0:0:0: [sdb] tag#0 CDB: opcode=0x28 28 00 04 02 ae 00 00 02 00 00 [ 7.179004] I/O error, dev sdb, sector 67284480 op 0x0:(READ) flags 0x80700 phys_seg 5 prio class 0 Fortunately, it appears that this ridiculous bug is avoided by setting the chain bit of Link TRBs on isochronous rings. Other ancient HCs are known which also expect the bit to be set and they ignore Link TRBs if it's not. Reportedly, 0.95 spec guaranteed that the bit is set. The bandwidth-starved NEC HC running a 32KB/uframe UVC endpoint reports tens of MSEs per second and runs into the bug within seconds. Chaining Link TRBs allows the same workload to run for many minutes, many times. No ne ---truncated---

View original source

05 / REFERENCES

Further evidence