In the Linux kernel, the following vulnerability has been resolved:
usb: typec: wcove: don't write past struct pd_message in wcove_read_rx_buffer()
wcove_read_rx_buffer() copies the PD RX FIFO into the caller's
struct pd_message with
for (i = 0; i < USBC_RXINFO_RXBYTES(info); i++)
regmap_read(wcove->regmap, USBC_RX_DATA + i, msg + i);
which has two problems:
USBC_RXINFO_RXBYTES() is a 5-bit field (max 31) while struct pd_message
is 30 bytes (__le16 header + __le32 payload[PD_MAX_PAYLOAD], packed).
The byte count latched in RXINFO is the number of bytes the port partner
put on the wire, so a malicious partner that transmits a 31-byte frame
can drive the loop one byte past the destination if the WCOVE BMC
receiver does not enforce the PD object-count limit in hardware. The
existing FIXME flagged this as unverified.
Independently, regmap_read() takes an unsigned int * and stores a full
unsigned int at the destination. Passing the byte pointer msg + i means
each iteration writes four bytes; the high three are zero (val_bits is
8) and are normally overwritten by the next iteration, but the final
iteration's high bytes are not. With RXBYTES == 30 the i == 29 iteration
already writes three zero bytes past msg, which sits on the IRQ thread's
stack in wcove_typec_irq().
Clamp the loop to sizeof(struct pd_message) and read each register into
a local before storing only its low byte, so the copy can never exceed
the destination regardless of what RXINFO reports.
usb: typec: wcove: don't write past struct pd_message in wcove_read_rx_buffer()
wcove_read_rx_buffer() copies the PD RX FIFO into the caller's
struct pd_message with
for (i = 0; i < USBC_RXINFO_RXBYTES(info); i++)
regmap_read(wcove->regmap, USBC_RX_DATA + i, msg + i);
which has two problems:
USBC_RXINFO_RXBYTES() is a 5-bit field (max 31) while struct pd_message
is 30 bytes (__le16 header + __le32 payload[PD_MAX_PAYLOAD], packed).
The byte count latched in RXINFO is the number of bytes the port partner
put on the wire, so a malicious partner that transmits a 31-byte frame
can drive the loop one byte past the destination if the WCOVE BMC
receiver does not enforce the PD object-count limit in hardware. The
existing FIXME flagged this as unverified.
Independently, regmap_read() takes an unsigned int * and stores a full
unsigned int at the destination. Passing the byte pointer msg + i means
each iteration writes four bytes; the high three are zero (val_bits is
8) and are normally overwritten by the next iteration, but the final
iteration's high bytes are not. With RXBYTES == 30 the i == 29 iteration
already writes three zero bytes past msg, which sits on the IRQ thread's
stack in wcove_typec_irq().
Clamp the loop to sizeof(struct pd_message) and read each register into
a local before storing only its low byte, so the copy can never exceed
the destination regardless of what RXINFO reports.
Metrics
Affected Vendors & Products
No data.
No data.
OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.
| Vendors | Products |
|---|---|
|
Linux
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|
Linux Kernel
Subscribe
|
Advisories
| Source | ID | Title |
|---|---|---|
 Ubuntu USN |
USN-8593-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-8603-1 | Linux kernel (Azure) vulnerabilities |
| Ubuntu USN |
USN-8618-1 | Linux kernel vulnerabilities |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Sun, 26 Jul 2026 08:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-119 CWE-120 CWE-787 |
Wed, 22 Jul 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-805 | |
| References |
|
Tue, 21 Jul 2026 23:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-119 CWE-120 CWE-787 |
Sun, 19 Jul 2026 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: usb: typec: wcove: don't write past struct pd_message in wcove_read_rx_buffer() wcove_read_rx_buffer() copies the PD RX FIFO into the caller's struct pd_message with for (i = 0; i < USBC_RXINFO_RXBYTES(info); i++) regmap_read(wcove->regmap, USBC_RX_DATA + i, msg + i); which has two problems: USBC_RXINFO_RXBYTES() is a 5-bit field (max 31) while struct pd_message is 30 bytes (__le16 header + __le32 payload[PD_MAX_PAYLOAD], packed). The byte count latched in RXINFO is the number of bytes the port partner put on the wire, so a malicious partner that transmits a 31-byte frame can drive the loop one byte past the destination if the WCOVE BMC receiver does not enforce the PD object-count limit in hardware. The existing FIXME flagged this as unverified. Independently, regmap_read() takes an unsigned int * and stores a full unsigned int at the destination. Passing the byte pointer msg + i means each iteration writes four bytes; the high three are zero (val_bits is 8) and are normally overwritten by the next iteration, but the final iteration's high bytes are not. With RXBYTES == 30 the i == 29 iteration already writes three zero bytes past msg, which sits on the IRQ thread's stack in wcove_typec_irq(). Clamp the loop to sizeof(struct pd_message) and read each register into a local before storing only its low byte, so the copy can never exceed the destination regardless of what RXINFO reports. | |
| Title | usb: typec: wcove: don't write past struct pd_message in wcove_read_rx_buffer() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-07-20T06:41:40.389Z
Reserved: 2026-07-19T07:54:57.023Z
Link: CVE-2026-63960
Vulnrichment
No data.
NVD
Status : Awaiting Analysis
Published: 2026-07-19T16:17:14.897
Modified: 2026-07-30T14:51:11.223
Link: CVE-2026-63960
Redhat
OpenCVE Enrichment
Updated: 2026-08-03T02:00:15Z
Weaknesses