In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_ncm: validate minimum block_len in ncm_unwrap_ntb()
The block_len read from the host-supplied NTB header is checked against
ntb_max but has no lower bound. When block_len is smaller than
opts->ndp_size, the bounds check of:
ndp_index > (block_len - opts->ndp_size)
will underflow producing a huge unsigned value that ndp_index can never
exceed, defeating the check entirely.
The same underflow occurs in the datagram index checks against block_len
- opts->dpe_size. With those checks neutered, a malicious USB host can
choose ndp_index and datagram offsets that point past the actual
transfer, and the skb_put_data() copies adjacent kernel memory into the
network skb.
Fix this by rejecting block lengths that cannot hold at least the NTB
header plus one NDP. This will make block_len - opts->ndp_size and
block_len - opts->dpe_size both well-defined.
Commit 8d2b1a1ec9f5 ("CDC-NCM: avoid overflow in sanity checking") fixed
a related class of issues on the host side of NCM.
References
Configurations
Configuration 1 (hide)
|
History
28 Apr 2026, 17:27
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| CWE | NVD-CWE-noinfo | |
| References | () https://git.kernel.org/stable/c/0f156bb5334e588034ca68ac2ee92b23f66e56e7 - Patch | |
| References | () https://git.kernel.org/stable/c/6762f8a95772265dd0c2ffe7f400493f3115b135 - Patch | |
| References | () https://git.kernel.org/stable/c/74908b0318d1df1188457040b8714ff4d4b68126 - Patch | |
| References | () https://git.kernel.org/stable/c/8757a2593631443648218244b9788e193ae0fdc1 - Patch | |
| References | () https://git.kernel.org/stable/c/8f993d30b95dc9557a8a96ceca11abed674c8acb - Patch | |
| References | () https://git.kernel.org/stable/c/d58ba8f6546232f8414f396c189297dbee03f1a7 - Patch | |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| First Time |
Linux
Linux linux Kernel |
27 Apr 2026, 14:16
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
27 Apr 2026, 12:16
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
24 Apr 2026, 15:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-04-24 15:16
Updated : 2026-04-28 17:27
NVD link : CVE-2026-31617
Mitre link : CVE-2026-31617
CVE.ORG link : CVE-2026-31617
JSON object : View
Products Affected
linux
- linux_kernel
CWE
