CVE-2025-22003

Description

In the Linux kernel, the following vulnerability has been resolved:can: ucan: fix out of bound read in strscpy() sourceCommit 7fdaf8966aae (can: ucan: use strscpy() to instead of strncpy())unintentionally introduced a one byte out of bound read on strscpy()ssource argument (which is kind of ironic knowing that strscpy() is meantto be a more secure alternative :)).Lets consider below buffers: dest[len + 1]; /* will be NUL terminated */ src[len]; /* may not be NUL terminated */When doing: strncpy(dest, src, len); dest[len] = 0;strncpy() will read up to len bytes from src.On the other hand: strscpy(dest, src, len + 1);will read up to len + 1 bytes from src, that is to say, an out of boundread of one byte will occur on src if it is not NUL terminated. Notethat the src[len] byte is never copied, but strscpy() still needs toread it to check whether a truncation occurred or not.This exact pattern happened in ucan.The root cause is that the source is not NUL terminated. Instead ofdoing a copy in a local buffer, directly NUL terminate it as soon asusb_control_msg() returns. With this, the local firmware_str[] variablecan be removed.On top of this do a couple refactors: - ucan_ctl_payload->raw is only used for the firmware string, so rename it to ucan_ctl_payload->fw_str and change its type from u8 to char. - ucan_device_request_in() is only used to retrieve the firmware string, so rename it to ucan_get_fw_str() and refactor it to make it directly handle all the string termination logic.

Risk Information

Associated Vulnerability

Patch Details

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234