CVE-2026-31607Critical· 9.8▾ MidnightIn 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 ur…
▾ Midnight zone — Critical, or high with PoC / in-the-wild
impact 53.9 · likelihood 0.1 · exploitation 0
Need a working PoC? Pro members can cast a request and our team develops one — it lands right here.
Exploit-prediction probability, daily snapshots since Jul 20.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
Last analysed / modified upstream
0.3%
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.
linux_kernel >= 2.6.39, < 6.6.136linux_kernel >= 6.7, < 6.12.83linux_kernel >= 6.13, < 6.18.24linux_kernel >= 6.19, < 6.19.14linux_kernel >= 7.0, < 7.0.1Upgrade past the affected range:
linux_kernel 7.0.1Connected by shared product, vendor, weakness, or advisory.
CVE-2022-0995High· 7.8An out-of-bounds (OOB) memory write flaw was found in the Linux kernel’s watch_queue event notification subsystem
CVE-2021-4090High· 7.1An out-of-bounds (OOB) memory write flaw was found in the NFSD in the Linux kernel
CVE-2023-6931High· 7.8A heap out-of-bounds write vulnerability in the Linux kernel's Performance Events system component can be exploited to achieve local privilege escalation. A perf_event's read_size can overflow, leading to an heap out-of-bounds increme…
CVE-2023-42753High· 7.0An array indexing vulnerability was found in the netfilter subsystem of the Linux kernel
CVE-2021-38166High· 7.8In kernel/bpf/hashtab.c in the Linux kernel through 5.13.8, there is an integer overflow and out-of-bounds write when many elements are placed in a single bucket
CVE-2026-31710Medium· 5.5In the Linux kernel, the following vulnerability has been resolved: smb: client: fix dir separator in SMB1 UNIX mounts When calling cifs_mount_get_tcon() with SMB1 UNIX mounts, @cifs_sb->mnt_cifs_flags needs to be read or updated only …