In the Linux kernel, the following vulnerability has been resolved:
usb: typec: tcpm: bound altmode_desc[] per iteration in svdm_consume_modes()
svdm_consume_modes() checks pmdata->altmodes against the array size once
before the loop over the count, but forgot to check the bound at every
point in the loop.
In the well-behaved SVDM discovery flow this is harmless because each of
at most SVID_DISCOVERY_MAX SVIDs contributes at most MODE_DISCOVERY_MAX
modes, exactly filling altmode_desc[ALTMODE_DISCOVERY_MAX]. But the
CMDT_RSP_ACK handler in tcpm_pd_svdm() does not correlate an incoming
ACK with any request the port actually sent. Once port->partner is set,
an unsolicited Discover Modes ACK is consumed unconditionally. A broken
or malicious port partner can therefore drive altmodes to
ALTMODE_DISCOVERY_MAX - 1 via the normal flow, and then send one extra
Discover Modes ACK with seven VDOs. Because the pre-loop check passes,
the loop could then writes up to five entries past altmode_desc[]. For
mode_data_prime the next field in struct tcpm_port is the
partner_altmode[] pointer array, which then receives partner-chosen
SVID/VDO bytes.
Move the bound check inside the loop so the array can never be indexed
past ALTMODE_DISCOVERY_MAX regardless of how many VDOs the partner
supplies or how the function was reached.
References
Configurations
Configuration 1 (hide)
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History
30 Oct 2026, 17:34
| Type | Values Removed | Values Added |
|---|---|---|
| CWE | NVD-CWE-noinfo | |
| CPE | cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* |
|
| References | () https://git.kernel.org/stable/c/3389c149c68c3fea61910ad5d34f7bf3bff44e32 - Patch | |
| References | () https://git.kernel.org/stable/c/4505f33dab56c274e82f47f94bf60a8cbf8f4b42 - Patch | |
| References | () https://git.kernel.org/stable/c/816c6251409db28f1b875988fcbd2ff1764a81f0 - Patch | |
| References | () https://git.kernel.org/stable/c/845598b154b9a92e9d279fafafa9405c121ae805 - Patch | |
| References | () https://git.kernel.org/stable/c/cbad85b446c06adbc5e5bed565871bb918ce9d32 - Patch | |
| References | () https://git.kernel.org/stable/c/f6694bac643c7ae25c0634b63e67d573ed31e5b7 - Patch | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| First Time |
Linux linux Kernel
Linux |
30 Oct 2026, 13:19
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
21 Oct 2026, 13:19
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Information
Published : 2026-07-19 16:17
Updated : 2026-10-30 17:34
NVD link : CVE-2026-63962
Mitre link : CVE-2026-63962
CVE.ORG link : CVE-2026-63962
JSON object : View
Products Affected
linux
- linux_kernel
CWE