CVE-2025-71197
kernel: w1: therm: Fix off-by-one buffer overflow in alarms_store
Severity
UnknownRed Hat Product Security
CVSS
Review impact separately from score.
Published · February 4, 2026
Updated · June 28, 2026
Description
In the Linux kernel, the following vulnerability has been resolved:
w1: therm: Fix off-by-one buffer overflow in alarms_store
The sysfs buffer passed to alarms_store() is allocated with 'size + 1' bytes and a NUL terminator is appended. However, the 'size' argument does not account for this extra byte. The original code then allocated 'size' bytes and used strcpy() to copy 'buf', which always writes one byte past the allocated buffer since strcpy() copies until the NUL terminator at index 'size'.
Fix this by parsing the 'buf' parameter directly using simple_strtoll() without allocating any intermediate memory or string copying. This removes the overflow while simplifying the code.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CWE not specified