usb: gadget: ncm: Avoid dropping datagrams of properly parsed NTBs
It is observed sometimes when tethering is used over NCM with Windows 11
as host, at some instances, the gadget_giveback has one byte appended at
the end of a proper NTB. When the NTB is parsed, unwrap call looks for
any leftover bytes in SKB provided by u_ether and if there are any pending
bytes, it treats them as a separate NTB and parses it. But in case the
second NTB (as per unwrap call) is faulty/corrupt, all the datagrams that
were parsed properly in the first NTB and saved in rx_list are dropped.
Adding a few custom traces showed the following:
[002] d..1 7828.532866: dwc3_gadget_giveback: ep1out:
req 000000003868811a length 1025/16384 zsI ==> 0
[002] d..1 7828.532867: ncm_unwrap_ntb: K: ncm_unwrap_ntb toprocess: 1025
[002] d..1 7828.532867: ncm_unwrap_ntb: K: ncm_unwrap_ntb nth: 1751999342
[002] d..1 7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb seq: 0xce67
[002] d..1 7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb blk_len: 0x400
[002] d..1 7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb ndp_len: 0x10
[002] d..1 7828.532869: ncm_unwrap_ntb: K: Parsed NTB with 1 frames
In this case, the giveback is of 1025 bytes and block length is 1024.
The rest 1 byte (which is 0x00) won't be parsed resulting in drop of
all datagrams in rx_list.
Same is case with packets of size 2048:
[002] d..1 7828.557948: dwc3_gadget_giveback: ep1out:
req 0000000011dfd96e length 2049/16384 zsI ==> 0
[002] d..1 7828.557949: ncm_unwrap_ntb: K: ncm_unwrap_ntb nth: 1751999342
[002] d..1 7828.557950: ncm_unwrap_ntb: K: ncm_unwrap_ntb blk_len: 0x800
Lecroy shows one byte coming in extra confirming that the byte is coming
in from PC:
Transfer 2959 - Bytes Transferred(1025) Timestamp((18.524 843 590)
- Transaction 8391 - Data(1025 bytes) Timestamp(18.524 843 590)
--- Packet 4063861
Data(1024 bytes)
Duration(2.117us) Idle(14.700ns) Timestamp(18.524 843 590)
--- Packet 4063863
Data(1 byte)
Duration(66.160ns) Time(282.000ns) Timestamp(18.524 845 722)
According to Windows driver, no ZLP is needed if wBlockLength is non-zero,
because the non-zero wBlockLength has already told the function side the
size of transfer to be expected. However, there are in-market NCM devices
that rely on ZLP as long as the wBlockLength is multiple of wMaxPacketSize.
To deal with such devices, it pads an extra 0 at end so the transfer is no
longer multiple of wMaxPacketSize.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-3840-1 | linux security update |
Debian DLA |
DLA-3842-1 | linux-5.10 security update |
Ubuntu USN |
USN-6820-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6820-2 | Linux kernel (NVIDIA) vulnerabilities |
Ubuntu USN |
USN-6821-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6821-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6821-3 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-6821-4 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-6828-1 | Linux kernel (Intel IoTG) vulnerabilities |
Ubuntu USN |
USN-6831-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6871-1 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-6892-1 | Linux kernel (IBM) vulnerabilities |
Ubuntu USN |
USN-6919-1 | Linux kernel vulnerabilities |
Tue, 08 Apr 2025 16:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Debian
Debian debian Linux |
|
| CPEs | cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.8:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.8:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.8:rc5:*:*:*:*:*:* |
|
| Vendors & Products |
Debian
Debian debian Linux |
Tue, 28 Jan 2025 17:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
ssvc
|
Fri, 22 Nov 2024 12:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Wed, 06 Nov 2024 08:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:a:linux:linux_kernel:-:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* |
|
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
| Metrics |
ssvc
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-11T20:10:23.186Z
Reserved: 2024-02-25T13:47:42.681Z
Link: CVE-2024-27405
Updated: 2024-08-02T00:34:52.278Z
Status : Analyzed
Published: 2024-05-17T12:15:10.500
Modified: 2025-04-08T15:53:55.357
Link: CVE-2024-27405
OpenCVE Enrichment
No data.
Debian DLA
Ubuntu USN