CVE-2026-63964

Summary

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.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/b41dfc033fe594e152648050e95b9489cd53e9e3
• https://git.kernel.org/stable/c/2f395ca1263bd181995eb829f5943a83a20db213
• https://git.kernel.org/stable/c/6526f8684f72391138353642af908803ba70795e
• https://git.kernel.org/stable/c/3f432b8203066c26770fe6ea591361f10021dd6b
• https://git.kernel.org/stable/c/c4ee519b06389e59ba2d6aa722fcc4a02a8bbcbb
• https://git.kernel.org/stable/c/a38ed87818b2419090fb1a6338ddce6842b65dfa
• https://git.kernel.org/stable/c/c8460de584fe5415d212cfdd127d4db90835a450
• https://git.kernel.org/stable/c/d7486952bf74e546ee3748fb14b2d07881fa6273

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