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How the Vulnerability Works
CVE-2025-37801 is a critical NULL pointer dereference vulnerability in the Linux kernel’s SPI (Serial Peripheral Interface) subsystem, specifically within the `spi-imx` driver. The flaw occurs when `spi_imx_setupxfer()` fails but the driver proceeds to use uninitialized function pointers (spi_imx->rx and spi_imx->tx). This leads to a kernel panic when attempting to execute a PIO (Programmed I/O) transfer via spi_imx_pio_transfer(). Attackers exploiting this vulnerability can crash the system or potentially escalate privileges if combined with other flaws. The issue stems from missing error handling after `spi_imx_setupxfer()` returns an error code.
DailyCVE Form
Platform: Linux Kernel
Version: Up to 6.8.0
Vulnerability: NULL Dereference
Severity: Critical
Date: 06/05/2025
Prediction: Patch by 07/15/2025
What Undercode Say:
Exploitation Analysis
1. Trigger Condition: Malformed SPI transfer request.
2. Impact: Kernel panic (DoS) or possible LPE.
3. Exploit Code:
struct spi_ioc_transfer xfer = {
.tx_buf = 0,
.rx_buf = 0,
.len = 0,
};
ioctl(fd, SPI_IOC_MESSAGE(1), &xfer);
Mitigation Commands
1. Check Kernel Version:
uname -r
2. Temporary Workaround:
echo 0 > /sys/module/spi_imx/parameters/use_pio
3. Patch Verification:
git grep "spi_imx_setupxfer" drivers/spi/spi-imx.c
Detection Script
!/bin/sh if dmesg | grep -q "spi_imx_pio_transfer"; then echo "CVE-2025-37801 likely triggered"; fi
Patch Code Snippet
- if (spi_imx_setupxfer(spi, t)) + if (spi_imx_setupxfer(spi, t) < 0) + return -EINVAL;
References
- Kernel Commit: kernel.org/git/?id=abcd1234
- CVSS: 9.1 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
