CVE-2024-26807 Affecting dlm-kmp-default package, versions <6.4.0-150600.23.7.3

Note: Versions mentioned in the description apply only to the upstream dlm-kmp-default package and not the dlm-kmp-default package as distributed by SLES. See How to fix? for SLES:15.6 relevant fixed versions and status.

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.

• https://www.suse.com/security/cve/CVE-2024-26807.html
• https://bugzilla.suse.com/1222801
• https://git.kernel.org/stable/c/03f1573c9587029730ca68503f5062105b122f61
• https://git.kernel.org/stable/c/32ce3bb57b6b402de2aec1012511e7ac4e7449dc
• https://git.kernel.org/stable/c/34e1d5c4407c78de0e3473e1fbf8fb74dbe66d03