CVE-2026-46246: 
Linux Debian vulnerability analysis and mitigation

CVE-2026-46246 is a use-after-free vulnerability in the Linux kernel's power: supply: pm8916_lbc driver (Qualcomm PM8916 Linear Battery Charger) affecting the IRQ handler's interaction with the extcon subsystem. The flaw arises from incorrect devm_ allocation ordering, creating a race condition during device removal. It was published on June 3, 2026, and affects Linux kernel versions 6.7–6.12.74, 6.13–6.18.13, and 6.19–6.19.3. It carries a CVSS v3.1 base score of 7.8 (High) (Github Advisory).

The root cause (CWE-416: Use After Free) lies in the pm8916_lbc driver registering its IRQ handler via devm_request_irq() before registering the extcon handle via its own devm_ call. Because devm_ resources are released in reverse allocation order during device removal, the extcon handle is freed before the IRQ handler is unregistered. This creates a race window where a hardware interrupt fires after extcon is freed but before the IRQ is torn down, causing extcon_set_state_sync() to be called with a dangling pointer — typically resulting in a kernel crash or silent memory corruption. The fix reorders the allocations so that devm_request_irq() is called only after the extcon handle is successfully registered, ensuring correct cleanup ordering (Github Advisory).

Successful exploitation can cause a system crash (denial of service) or silent kernel memory corruption, potentially affecting confidentiality, integrity, and availability of the entire system (all rated High in the CVSS assessment). Because the vulnerability resides in kernel space, memory corruption could theoretically be leveraged for privilege escalation on affected devices, though no such exploitation chain has been publicly demonstrated. The affected driver is specific to devices using the Qualcomm PM8916 PMIC (common in certain ARM-based mobile/embedded platforms), limiting the scope to systems running that hardware (Github Advisory).

Apply the upstream kernel patches that reorder devm_ allocations in the pm8916_lbc driver so the IRQ is requested after the extcon handle is registered. Fixed versions are Linux kernel 6.12.75, 6.18.14, and 6.19.4 (and mainline 7.0+). Patches are available at the following stable kernel commits: 23067259, 47abfc20, 48e0f68b, and 9fab0120. Systems not using PM8916-based hardware are not affected and do not require action (Github Advisory).