The Linux kernel’s msc313e watchdog driver contains a bug that causes the clock reference counter to be incremented every time the settimeout() function is called while the watchdog is active, without a matching decrement when the driver is stopped. In addition, calling settimeout() when the watchdog is not running starts the hardware timer regardless of the intended timeout. These flaws can lead to resource leakage and unintended watchdog activations, potentially disrupting normal operation. The vulnerability originates from the unconditional call to msc313e_wdt_start() in settimeout(), which introduces the counter imbalance and spurious timer behavior. The impact is limited to systems running a kernel build that includes the affected driver and has not yet incorporated the patch commit.

All Linux kernel builds that include the msc313e watchdog driver are affected if the patch commit has not been applied. The commit 2152a13ee2a9af09a668ebd053a8dbf771dadb80, referenced in the advisory, applies the fix. Since the advisory lists the vendor as Linux, the scope covers all flavors of the Linux kernel.

The CVSS score of 5.5 indicates moderate severity. The EPSS score of < 1% suggests a very low likelihood of current exploitation. The vulnerability is not listed in the CISA KEV catalog, further implying limited real‑world exploitation. Based on the description, it is inferred that an attacker would require local access to the watchdog device—commonly root or a user with permission to write to the /dev/watchdog interface—to trigger the flaw. If triggered repeatedly, the unbalanced reference count could deplete kernel resources, and the accidental activation of the hardware timer could cause unintended system resets. However, no public exploit is known to date.