CVE-2026-80827
USB: serial: option: fix slab OOB read in interrupt URB callback
Published Sep 4, 2026
CVSS n/a
EPSS < 1%
KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:
USB: serial: option: fix slab OOB read in interrupt URB callback
The interrupt URB buffer is allocated in setup_port_interrupt_in() based
on the endpoint's wMaxPacketSize:
buffer_size = usb_endpoint_maxp(epd);
port->interrupt_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
When a USB device declares wMaxPacketSize = 8 on its interrupt IN
endpoint, the buffer is allocated from kmalloc-8 cache (exactly
8 bytes).
If the device sends a short packet (actual_length < wMaxPacketSize),
the URB completes with status == 0 and the callback proceeds to read:
data[sizeof(struct usb_ctrlrequest)]
which evaluates to data[8], accessing 1 byte beyond the allocated 8-byte
buffer. This results in a slab out-of-bounds read.
Fix this by adding the missing bounds check: first verify that the
actual length is large enough to contain the struct usb_ctrlrequest
header before accessing req_pkt->bRequestType and req_pkt->bRequest,
and then verify that there is an additional byte for the modem signal
state before reading data[sizeof(struct usb_ctrlrequest)] inside the
conditional. Use sizeof(*req_pkt) instead of sizeof(struct
usb_ctrlrequest) for consistency.
[ johan: use dev_err(); split signals declaration and initialisation ]
USB: serial: option: fix slab OOB read in interrupt URB callback
The interrupt URB buffer is allocated in setup_port_interrupt_in() based
on the endpoint's wMaxPacketSize:
buffer_size = usb_endpoint_maxp(epd);
port->interrupt_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
When a USB device declares wMaxPacketSize = 8 on its interrupt IN
endpoint, the buffer is allocated from kmalloc-8 cache (exactly
8 bytes).
If the device sends a short packet (actual_length < wMaxPacketSize),
the URB completes with status == 0 and the callback proceeds to read:
data[sizeof(struct usb_ctrlrequest)]
which evaluates to data[8], accessing 1 byte beyond the allocated 8-byte
buffer. This results in a slab out-of-bounds read.
Fix this by adding the missing bounds check: first verify that the
actual length is large enough to contain the struct usb_ctrlrequest
header before accessing req_pkt->bRequestType and req_pkt->bRequest,
and then verify that there is an additional byte for the modem signal
state before reading data[sizeof(struct usb_ctrlrequest)] inside the
conditional. Use sizeof(*req_pkt) instead of sizeof(struct
usb_ctrlrequest) for consistency.
[ johan: use dev_err(); split signals declaration and initialisation ]
Affected Products
-
CVE record
-
NVD configurations
No data
-
Red Hat packages
No data
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OpenCVE enrichment
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
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| Linux | Linux | affected |
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No data.
No data.
| Vendor | Product | Versions | ||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux Kernel |
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| Linux | Linux Kernel |
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Remediation
Tracking
Advisories
| Source | ID | Title |
|---|---|---|
 Debian DLA |
DLA-4777-1 | linux security update |
| Debian DLA |
DLA-4817-1 | linux-6.12 security update |
 Debian DSA |
DSA-6528-1 | linux security update |
 Ubuntu USN |
USN-8961-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-9019-1 | Linux kernel (Azure) vulnerabilities |
| Ubuntu USN |
USN-9020-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-9022-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-9023-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-9024-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-9025-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-9026-1 | Linux kernel (Azure) vulnerabilities |
| Ubuntu USN |
USN-9029-1 | Linux kernel (Raspberry Pi) vulnerabilities |
| Ubuntu USN |
USN-9039-1 | Linux kernel (Azure CVM) vulnerabilities |
| Ubuntu USN |
USN-9040-1 | Linux kernel (Low Latency NVIDIA) vulnerabilities |
| Ubuntu USN |
USN-9066-1 | Linux kernel (HWE) vulnerabilities |
| Ubuntu USN |
USN-9091-1 | Linux kernel (NVIDIA Tegra) vulnerabilities |
Metrics
No CVSS v4.0
No CVSS v3.1
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.195% probability within 30 days)
Key SSVC decision points have not yet been added.
References
History
Sep 4, 2026 7:15 PM
Weaknesses updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-125 CWE-20 |
Sep 4, 2026 4:00 PM
Description updated. Title updated. First appearance in the feed. Affected versions updated. Affected vendors updated. Added references
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: USB: serial: option: fix slab OOB read in interrupt URB callback The interrupt URB buffer is allocated in setup_port_interrupt_in() based on the endpoint's wMaxPacketSize: buffer_size = usb_endpoint_maxp(epd); port->interrupt_in_buffer = kmalloc(buffer_size, GFP_KERNEL); When a USB device declares wMaxPacketSize = 8 on its interrupt IN endpoint, the buffer is allocated from kmalloc-8 cache (exactly 8 bytes). If the device sends a short packet (actual_length < wMaxPacketSize), the URB completes with status == 0 and the callback proceeds to read: data[sizeof(struct usb_ctrlrequest)] which evaluates to data[8], accessing 1 byte beyond the allocated 8-byte buffer. This results in a slab out-of-bounds read. Fix this by adding the missing bounds check: first verify that the actual length is large enough to contain the struct usb_ctrlrequest header before accessing req_pkt->bRequestType and req_pkt->bRequest, and then verify that there is an additional byte for the modem signal state before reading data[sizeof(struct usb_ctrlrequest)] inside the conditional. Use sizeof(*req_pkt) instead of sizeof(struct usb_ctrlrequest) for consistency. [ johan: use dev_err(); split signals declaration and initialisation ] | |
| Title | USB: serial: option: fix slab OOB read in interrupt URB callback | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
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