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How the Mentioned CVE Works
The vulnerability CVE-2025-37979 is a buffer overflow in the Qualcomm LPASS (Low Power Audio Subsystem) driver for the sc7280 SoC within the Linux kernel. The flaw originates from commit 5f78e1fb7a3e (“ASoC: qcom: Add driver support for audioreach solution”), which introduced new case values for audio port identifiers (like RX_CODEC_DMA_RX_0). The driver’s `sc7280_snd_hw_params()` function uses these identifiers as indexes into fixed-size arrays. However, the `LPASS_MAX_PORTS` constant was not updated to reflect the new maximum port ID. When the driver processes hardware parameters for a high port number, it calculates an array index that exceeds the actual allocated buffer size. This leads to an out-of-bounds write in kernel memory, corrupting adjacent data structures. The overflow occurs because the check against `LPASS_MAX_PORTS` is ineffective, allowing illegal index access. This memory corruption can be triggered from user space by an application configuring specific audio paths on affected sc7280 hardware, potentially leading to a kernel crash or privilege escalation.
DailyCVE Form
Platform: Linux Kernel
Version: sc7280 LPASS driver
Vulnerability: Buffer Overflow
Severity: Critical
Date: 2025-05-20
Prediction: 2026-01-15
What Undercode Say
Analytics
`uname -r` Check kernel version
`dmesg | grep -i lpass` Monitor driver errors
`cat /proc/device-tree/compatible` Verify SoC
Code Snippet (Vulnerable Case):
switch (port_id) {
case RX_CODEC_DMA_RX_0: // New, high-value ID
index = port_id - BASE_INDEX; // May overflow array
break;
// ... other cases
}
if (port_id >= LPASS_MAX_PORTS) return -EINVAL; // Check is too low
How Exploit
An exploit would craft audio configuration calls to the ALSA (Advanced Linux Sound Architecture) subsystem, targeting the vulnerable `sc7280_snd_hw_params()` function. By specifying a high port identifier (like RX_CODEC_DMA_RX_0), the attacker triggers the out-of-bounds array write. Careful manipulation of the written data could corrupt kernel function pointers or critical data structures to gain elevated privileges or cause a denial of service (kernel panic).
Protection from this CVE
Apply kernel patch redefining LPASS_MAX_PORTS. Update to a kernel version containing the fix. Restrict access to privileged audio functions.
Impact
Kernel memory corruption leading to system crash, denial of service, or potential local privilege escalation.
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Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
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