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.
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/spi/spi-cadence-quadspi.c"
],
"versions": [
{
"version": "2087e85bb66e",
"lessThan": "03f1573c9587",
"status": "affected",
"versionType": "git"
},
{
"version": "2087e85bb66e",
"lessThan": "34e1d5c4407c",
"status": "affected",
"versionType": "git"
},
{
"version": "2087e85bb66e",
"lessThan": "32ce3bb57b6b",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/spi/spi-cadence-quadspi.c"
],
"versions": [
{
"version": "6.4",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.4",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.6.21",
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.7.9",
"lessThanOrEqual": "6.7.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.8",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]