CVE-2026-31607
- Source
- https://cve.org/CVERecord?id=CVE-2026-31607
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-31607.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2026-31607
- Downstream
- Related
- Published
- 2026-04-24T14:42:29Z
- Modified
- 2026-08-27T18:27:27Z
- Severity
-
- 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
- Summary
- usbip: validate number_of_packets in usbip_pack_ret_submit()
- Details
-
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.
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31607.json" }- References
-
- https://git.kernel.org/stable/c/2ab833a16a825373aad2ba7d54b572b277e95b71
- https://git.kernel.org/stable/c/5e1c4ece08ccdc197177631f111845a2c68eede3
- https://git.kernel.org/stable/c/885c8591784da6314f9aa82fa460ac69f9f79e5f
- https://git.kernel.org/stable/c/8d155e2d1c4102f74f82a2bf9c016164bb0f7384
- https://git.kernel.org/stable/c/906f16a836de13fe61f49cdce2f66f2dbd14caf4
- https://git.kernel.org/stable/c/ef8ebb1c637b4cfb61a9dd2e013376774ee2033b
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31607.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-31607
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced1325f85fa49f57df034869de430f7c302ae23109Fixed885c8591784da6314f9aa82fa460ac69f9f79e5fFixed8d155e2d1c4102f74f82a2bf9c016164bb0f7384Fixed906f16a836de13fe61f49cdce2f66f2dbd14caf4Fixedef8ebb1c637b4cfb61a9dd2e013376774ee2033bFixed5e1c4ece08ccdc197177631f111845a2c68eede3Fixed2ab833a16a825373aad2ba7d54b572b277e95b71
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced0 Unknown introduced commit / All previous commits are affectedLast Affectedd9638d9236eed035a575feddec61d036dacc2676Last Affectedca7d3501b7a287c18b5b470e871d3029b0f4842aLast Affected1ce528277e1a66856ed3f7526c1e3458c0ed4a70Last Affecteddb898d0c5c493ce4177d5e1d3a953e079a56a24bLast Affected5aa02704b9ee67c5b2ee26d54c5f4eb99e93ba9a
Affected versions
v2.*
Linux / Kernel
Package
- Name
- Kernel