CVE-2024-35825

usb: gadget: ncm: Fix handling of zero block length packets

Published May 17, 2024 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

usb: gadget: ncm: Fix handling of zero block length packets

While connecting to a Linux host with CDC_NCM_NTB_DEF_SIZE_TX
set to 65536, it has been observed that we receive short packets,
which come at interval of 5-10 seconds sometimes and have block
length zero but still contain 1-2 valid datagrams present.

According to the NCM spec:

"If wBlockLength = 0x0000, the block is terminated by a
short packet. In this case, the USB transfer must still
be shorter than dwNtbInMaxSize or dwNtbOutMaxSize. If
exactly dwNtbInMaxSize or dwNtbOutMaxSize bytes are sent,
and the size is a multiple of wMaxPacketSize for the
given pipe, then no ZLP shall be sent.

wBlockLength= 0x0000 must be used with extreme care, because
of the possibility that the host and device may get out of
sync, and because of test issues.

wBlockLength = 0x0000 allows the sender to reduce latency by
starting to send a very large NTB, and then shortening it when
the sender discovers that there’s not sufficient data to justify
sending a large NTB"

However, there is a potential issue with the current implementation,
as it checks for the occurrence of multiple NTBs in a single
giveback by verifying if the leftover bytes to be processed is zero
or not. If the block length reads zero, we would process the same
NTB infintely because the leftover bytes is never zero and it leads
to a crash. Fix this by bailing out if block length reads zero.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Debian DLA Debian DLA DLA-3840-1 linux security update
Debian DLA Debian DLA DLA-3842-1 linux-5.10 security update
Ubuntu USN Ubuntu USN USN-6896-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6896-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6896-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6896-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6896-5 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6898-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6898-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6898-3 Linux kernel kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6898-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6917-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6919-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6927-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7019-1 Linux kernel vulnerabilities
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Debian
Debian debian Linux
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.6:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.6:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.6:rc7:*:*:*:*:*:*
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:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc7:*:*:*:*:*:*
Vendors & Products Debian
Debian debian Linux
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
May 23, 2026, 3:43 PM
Reserved
May 17, 2024, 12:19 PM
Status
Analyzed
Published
May 17, 2024, 2:15 PM
Modified
Jun 17, 2026, 7:35 AM
Severity
Moderate
Public date
May 17, 2024, 12:00 AM