In the Linux kernel, the following vulnerability has been resolved:
usbip: validate number_of_packets in usbip_pack_ret_submit()
When a USB/IP client receives a RET_SUBMIT response,
usbip_pack_ret_submit() unconditionally overwrites
urb->number_of_packets from the network PDU. This value is
subsequently used as the loop bound in usbip_recv_iso() and
usbip_pad_iso() to iterate over urb->iso_frame_desc[], a flexible
array whose size was fixed at URB allocation time based on the
*original* number_of_packets from the CMD_SUBMIT.
A malicious USB/IP server can set number_of_packets in the response
to a value larger than what was originally submitted, causing a heap
out-of-bounds write when usbip_recv_iso() writes to
urb->iso_frame_desc[i] beyond the allocated region.
KASAN confirmed this with kernel 7.0.0-rc5:
BUG: KASAN: slab-out-of-bounds in usbip_recv_iso+0x46a/0x640
Write of size 4 at addr ffff888106351d40 by task vhci_rx/69
The buggy address is located 0 bytes to the right of
allocated 320-byte region [ffff888106351c00, ffff888106351d40)
The server side (stub_rx.c) and gadget side (vudc_rx.c) already
validate number_of_packets in the CMD_SUBMIT path since commits
c6688ef9f297 ("usbip: fix stub_rx: harden CMD_SUBMIT path to handle
malicious input") and b78d830f0049 ("usbip: fix vudc_rx: harden
CMD_SUBMIT path to handle malicious input"). The server side validates
against USBIP_MAX_ISO_PACKETS because no URB exists yet at that point.
On the client side we have the original URB, so we can use the tighter
bound: the response must not exceed the original number_of_packets.
This mirrors the existing validation of actual_length against
transfer_buffer_length in usbip_recv_xbuff(), which checks the
response value against the original allocation size.
Kelvin Mbogo's series ("usb: usbip: fix integer overflow in
usbip_recv_iso()", v2) hardens the receive-side functions themselves;
this patch complements that work by catching the bad value at its
source -- in usbip_pack_ret_submit() before the overwrite -- and
using the tighter per-URB allocation bound rather than the global
USBIP_MAX_ISO_PACKETS limit.
Fix this by checking rpdu->number_of_packets against
urb->number_of_packets in usbip_pack_ret_submit() before the
overwrite. On violation, clamp to zero so that usbip_recv_iso() and
usbip_pad_iso() safely return early.
References
Configurations
Configuration 1 (hide)
|
History
28 Apr 2026, 15:11
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Linux
Linux linux Kernel |
|
| CWE | CWE-787 | |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| References | () https://git.kernel.org/stable/c/2ab833a16a825373aad2ba7d54b572b277e95b71 - Patch | |
| References | () https://git.kernel.org/stable/c/5e1c4ece08ccdc197177631f111845a2c68eede3 - Patch | |
| References | () https://git.kernel.org/stable/c/885c8591784da6314f9aa82fa460ac69f9f79e5f - Patch | |
| References | () https://git.kernel.org/stable/c/8d155e2d1c4102f74f82a2bf9c016164bb0f7384 - Patch | |
| References | () https://git.kernel.org/stable/c/906f16a836de13fe61f49cdce2f66f2dbd14caf4 - Patch | |
| References | () https://git.kernel.org/stable/c/ef8ebb1c637b4cfb61a9dd2e013376774ee2033b - Patch |
27 Apr 2026, 15:16
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 9.8 |
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 15:11
NVD link : CVE-2026-31607
Mitre link : CVE-2026-31607
CVE.ORG link : CVE-2026-31607
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-787
Out-of-bounds Write