CVE-2024-26807

In the Linux kernel, the following vulnerability has been resolved:

Both cadence-quadspi ->runtime_suspend() and ->runtime_resume() implementations start with:

struct cqspi_st *cqspi = dev_get_drvdata(dev);
struct spi_controller *host = dev_get_drvdata(dev);

This obviously cannot be correct, unless struct cqspi_st is the first member of struct spi_controller, or the other way around, but it is not the case. struct spi_controller is allocated by devm_spi_alloc_host(), which allocates an extra amount of memory for private data, used to store struct cqspi_st.

The ->probe() function of the cadence-quadspi driver then sets the device drvdata to store the address of the struct cqspi_st structure. Therefore:

struct cqspi_st *cqspi = dev_get_drvdata(dev);

is correct, but:

struct spi_controller *host = dev_get_drvdata(dev);

is not, as it makes host point not to a struct spi_controller but to the same struct cqspi_st structure as above.

This obviously leads to bad things (memory corruption, kernel crashes) directly during ->probe(), as ->probe() enables the device using PM runtime, leading the ->runtime_resume() hook being called, which in turns calls spi_controller_resume() with the wrong pointer.

This has at least been reported [0] to cause a kernel crash, but the exact behavior will depend on the memory contents.

[0] https://lore.kernel.org/all/20240226121803.5a7r5wkpbbowcxgx@dhruva/

This issue potentially affects all platforms that are currently using the cadence-quadspi driver.

Weakness

The product writes data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

• For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer.

• Be wary that a language’s interface to native code may still be subject to overflows, even if the language itself is theoretically safe.

• Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

• Examples include the Safe C String Library (SafeStr) by Messier and Viega [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions.

• Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking.

• D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.

• Consider adhering to the following rules when allocating and managing an application’s memory:

• Run or compile the software using features or extensions that randomly arrange the positions of a program’s executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.

• Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as “rebasing” (for Windows) and “prelinking” (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.

• For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].

• Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX [REF-60] [REF-61]. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment.

• For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND [REF-1336].

References

• https://git.kernel.org/stable/c/03f1573c9587029730ca68503f5062105b122f61
• https://git.kernel.org/stable/c/2c914aac9522f6e93822c18dff233d3e92399c81
• https://git.kernel.org/stable/c/32ce3bb57b6b402de2aec1012511e7ac4e7449dc
• https://git.kernel.org/stable/c/34e1d5c4407c78de0e3473e1fbf8fb74dbe66d03
• https://git.kernel.org/stable/c/03f1573c9587029730ca68503f5062105b122f61
• https://git.kernel.org/stable/c/32ce3bb57b6b402de2aec1012511e7ac4e7449dc
• https://git.kernel.org/stable/c/34e1d5c4407c78de0e3473e1fbf8fb74dbe66d03
• https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html