Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: ccg: reject firmware images without a ':' record header do_flash() locates the first .cyacd record with p = strnchr(fw->data, fw->size, ':'); while (p < eof) { s = strnchr(p + 1, eof - p - 1, ':'); ... } If the firmware image contains no ':' byte, strnchr() returns NULL. NULL compares less than the valid kernel pointer eof, so the loop body runs and strnchr() is called with p + 1 == (void *)1 and a length of roughly (unsigned long)eof, causing a wonderful crash. The not_signed_fw fallthrough earlier in do_flash() and the chip-state branches in ccg_fw_update_needed() allow an unsigned blob to reach this loop, so a root user who can place a crafted file under /lib/firmware and write the do_flash sysfs attribute can trigger the oops. Bail out with -EINVAL when the initial strnchr() returns NULL.
References
- https://git.kernel.org/stable/c/2f395ca1263bd181995eb829f5943a83a20db213
- https://git.kernel.org/stable/c/3f432b8203066c26770fe6ea591361f10021dd6b
- https://git.kernel.org/stable/c/6526f8684f72391138353642af908803ba70795e
- https://git.kernel.org/stable/c/a38ed87818b2419090fb1a6338ddce6842b65dfa
- https://git.kernel.org/stable/c/b41dfc033fe594e152648050e95b9489cd53e9e3
- https://git.kernel.org/stable/c/c4ee519b06389e59ba2d6aa722fcc4a02a8bbcbb
- https://git.kernel.org/stable/c/c8460de584fe5415d212cfdd127d4db90835a450
- https://git.kernel.org/stable/c/d7486952bf74e546ee3748fb14b2d07881fa6273
FAQ
What is CVE-2026-63964?
CVE-2026-63964 is a documented vulnerability. In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: ccg: reject firmware images without a ':' record header do_flash() locates the first .cyacd record with p = st...
How severe is CVE-2026-63964?
CVSS scoring is not yet available for CVE-2026-63964. Check NVD for updates.
Is there a patch for CVE-2026-63964?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.