U.S. flag   An official website of the United States government
Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock (Dot gov) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Vulnerability Change Records for CVE-2024-27405

Change History

New CVE Received from kernel.org 5/17/2024 8:15:10 AM

Action Type Old Value New Value
Added Description

								
							
							
						
In the Linux kernel, the following vulnerability has been resolved:

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.
Added Reference

								
							
							
						
kernel.org https://git.kernel.org/stable/c/059285e04ebb273d32323fbad5431c5b94f77e48 [No types assigned]
Added Reference

								
							
							
						
kernel.org https://git.kernel.org/stable/c/2b7ec68869d50ea998908af43b643bca7e54577e [No types assigned]
Added Reference

								
							
							
						
kernel.org https://git.kernel.org/stable/c/2cb66b62a5d64ccf09b0591ab86fb085fa491fc5 [No types assigned]
Added Reference

								
							
							
						
kernel.org https://git.kernel.org/stable/c/35b604a37ec70d68b19dafd10bbacf1db505c9ca [No types assigned]
Added Reference

								
							
							
						
kernel.org https://git.kernel.org/stable/c/57ca0e16f393bb21d69734e536e383a3a4c665fd [No types assigned]
Added Reference

								
							
							
						
kernel.org https://git.kernel.org/stable/c/76c51146820c5dac629f21deafab0a7039bc3ccd [No types assigned]
Added Reference

								
							
							
						
kernel.org https://git.kernel.org/stable/c/a31cf46d108dabce3df80b3e5c07661e24912151 [No types assigned]
Added Reference

								
							
							
						
kernel.org https://git.kernel.org/stable/c/c7f43900bc723203d7554d299a2ce844054fab8e [No types assigned]