The DeviceTree Specification v0.3 specifies that the cache node '[d-|i-|]cache-size' property is required. The 'cache-unified' property is specifies whether the cache level is separate or unified. If the cache-size property is missing, no cache leaves is accounted. This can lead to a 'BUG: KASAN: slab-out-of-bounds' [1] bug. Check 'cache-unified' property and always account for at least one cache leave when parsing the device tree. [1] https://lore.kernel.org/all/0f19cb3f-d6cf-4032-66d2-dedc9d09a0e3@xxxxxxxxxx/ Reported-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> Signed-off-by: Pierre Gondois <pierre.gondois@xxxxxxx> --- drivers/base/cacheinfo.c | 37 ++++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 11 deletions(-) diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c index 3e965ef6ee42..339cd1e3d5af 100644 --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -225,12 +225,9 @@ static int cache_setup_of_node(unsigned int cpu) return 0; } -int init_of_cache_level(unsigned int cpu) +static int of_count_cache_leaves(struct device_node *np) { - struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); - struct device_node *np = of_cpu_device_node_get(cpu); - struct device_node *prev = NULL; - unsigned int levels = 0, leaves = 0, level; + unsigned int leaves = 0; if (of_property_read_bool(np, "cache-size")) ++leaves; @@ -238,6 +235,28 @@ int init_of_cache_level(unsigned int cpu) ++leaves; if (of_property_read_bool(np, "d-cache-size")) ++leaves; + + if (!leaves) { + /* The '[i-|d-|]cache-size' property is required, but + * if absent, fallback on the 'cache-unified' property. + */ + if (of_property_read_bool(np, "cache-unified")) + return 1; + else + return 2; + } + + return leaves; +} + +int init_of_cache_level(unsigned int cpu) +{ + struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); + struct device_node *np = of_cpu_device_node_get(cpu); + struct device_node *prev = NULL; + unsigned int levels = 0, leaves, level; + + leaves = of_count_cache_leaves(np); if (leaves > 0) levels = 1; @@ -251,12 +270,8 @@ int init_of_cache_level(unsigned int cpu) goto err_out; if (level <= levels) goto err_out; - if (of_property_read_bool(np, "cache-size")) - ++leaves; - if (of_property_read_bool(np, "i-cache-size")) - ++leaves; - if (of_property_read_bool(np, "d-cache-size")) - ++leaves; + + leaves += of_count_cache_leaves(np); levels = level; } -- 2.25.1
