CVE-2026-31617

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.
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

History

28 Apr 2026, 17:27

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 5.5
CWE NVD-CWE-noinfo
References () https://git.kernel.org/stable/c/0f156bb5334e588034ca68ac2ee92b23f66e56e7 - () https://git.kernel.org/stable/c/0f156bb5334e588034ca68ac2ee92b23f66e56e7 - Patch
References () https://git.kernel.org/stable/c/6762f8a95772265dd0c2ffe7f400493f3115b135 - () https://git.kernel.org/stable/c/6762f8a95772265dd0c2ffe7f400493f3115b135 - Patch
References () https://git.kernel.org/stable/c/74908b0318d1df1188457040b8714ff4d4b68126 - () https://git.kernel.org/stable/c/74908b0318d1df1188457040b8714ff4d4b68126 - Patch
References () https://git.kernel.org/stable/c/8757a2593631443648218244b9788e193ae0fdc1 - () https://git.kernel.org/stable/c/8757a2593631443648218244b9788e193ae0fdc1 - Patch
References () https://git.kernel.org/stable/c/8f993d30b95dc9557a8a96ceca11abed674c8acb - () https://git.kernel.org/stable/c/8f993d30b95dc9557a8a96ceca11abed674c8acb - Patch
References () https://git.kernel.org/stable/c/d58ba8f6546232f8414f396c189297dbee03f1a7 - () 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
  • () https://git.kernel.org/stable/c/0f156bb5334e588034ca68ac2ee92b23f66e56e7 -

27 Apr 2026, 12:16

Type Values Removed Values Added
References
  • () https://git.kernel.org/stable/c/8f993d30b95dc9557a8a96ceca11abed674c8acb -

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