CVE-2026-93272 in Linux
Summary
by MITRE • 09/24/2026
In the Linux kernel, the following vulnerability has been resolved:
remoteproc: qcom_wcnss: Fix handling the lack of PD regulators in v3
The changes introduced to handle single power domain platforms have swapped the info pointer increment from num_pd_vregs to num_pds, which would shift the info pointer past the end of the array for pronto-v3, which does not list power domain regulators in vregs.
This showed up as a difference between GCC- and LLVM-compiled kernels on SDM632 devices, where only with LLVM one would get the "regulator request with no identifier" error, because the out-of-bounds memory ended up being zeroed. Fix by skipping the increment when there are more power domains than regulators.
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Analysis
by VulDB Data Team • 09/24/2026
The vulnerability identified in the Linux kernel's remoteproc subsystem for Qualcomm WCNSS devices represents a critical off-by-one logic error within the driver initialization sequence, specifically affecting platforms that utilize version three of the hardware interface such as those based on the SDM632 chipset. This flaw originates from an incorrect pointer arithmetic operation during the handling of power domain regulators. The code was designed to manage single power domain configurations by iterating through a list of power domains and their associated voltage regulators. However, the implementation erroneously incremented the information pointer using the total count of power domains rather than the actual number of valid regulator entries. This logical inconsistency causes the driver to access memory locations beyond the bounds of the allocated array when processing devices like pronto-v3 that do not define power domain regulators in their vregs structure.
From a technical perspective, this issue is classified as an out-of-bounds read vulnerability, which aligns with CWE-125 specifications regarding improper validation of array indices or buffer boundaries. The root cause lies in the failure to distinguish between the number of logical power domains and the physical regulators available for those domains. When the driver attempts to request a regulator using an index derived from the total domain count instead of the actual regulator count, it reads uninitialized or zeroed memory depending on the compiler used. This discrepancy highlights a significant difference in how GCC and LLVM handle stack allocation and initialization; while GCC may leave the out-of-bounds memory with indeterminate values leading to unpredictable behavior, LLVM tends to zero-initialize such regions, resulting in specific error messages like regulator request with no identifier. Despite these differing manifestations, both scenarios indicate that the driver is operating on invalid data structures, which compromises system stability and reliability.
The operational impact of this vulnerability extends beyond simple initialization failures. In a production environment, accessing out-of-bounds memory can lead to kernel panics or unexpected reboots if the read values trigger subsequent logic errors in power management routines. Furthermore, incorrect regulator handling can prevent wireless connectivity subsystems from powering up correctly, effectively rendering network capabilities on affected devices non-functional. This constitutes an availability impact as defined by the CIA triad and maps to ATT&CK technique T1496 regarding resource hijacking or denial of service through system instability. The vulnerability is particularly insidious because it may not manifest consistently across all builds due to compiler-specific memory initialization behaviors, making debugging difficult for developers who rely on standard testing environments that might mask the issue by chance.
Mitigation strategies must address both immediate remediation and long-term defensive coding practices. The primary fix involves modifying the remoteproc driver logic to strictly validate regulator counts against domain counts before incrementing pointers or accessing array elements. Developers should implement explicit checks to ensure that index operations remain within the bounds of the allocated vregs array, thereby preventing out-of-bounds reads. Additionally, adopting static analysis tools and fuzzing techniques during the development lifecycle can help identify similar pointer arithmetic errors before they reach production kernels. For system administrators managing affected devices, applying kernel patches that include this specific fix is essential to restore proper functionality and prevent potential denial of service conditions caused by regulator initialization failures. Ensuring consistent compiler flags and rigorous code review processes focusing on array bounds checking will further reduce the risk of similar vulnerabilities in future updates.