if users give a name saved in stack, the current code will generate magic pointer. if users don't give a name(NULL), kasprintf() will always return NULL as we are at the early stage. that means cma_init_reserved_mem() will return -ENOMEM if users set name parameter as NULL. Cc: Roman Gushchin <guro@xxxxxx> Signed-off-by: Barry Song <song.bao.hua@xxxxxxxxxxxxx> --- mm/cma.c | 13 ++++++------- mm/cma.h | 4 +++- 2 files changed, 9 insertions(+), 8 deletions(-) diff --git a/mm/cma.c b/mm/cma.c index 0463ad2ce06b..b24151fa2101 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -202,13 +202,12 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, * subsystems (like slab allocator) are available. */ cma = &cma_areas[cma_area_count]; - if (name) { - cma->name = name; - } else { - cma->name = kasprintf(GFP_KERNEL, "cma%d\n", cma_area_count); - if (!cma->name) - return -ENOMEM; - } + + if (name) + snprintf(cma->name, CMA_MAX_NAME, name); + else + snprintf(cma->name, CMA_MAX_NAME, "cma%d\n", cma_area_count); + cma->base_pfn = PFN_DOWN(base); cma->count = size >> PAGE_SHIFT; cma->order_per_bit = order_per_bit; diff --git a/mm/cma.h b/mm/cma.h index 33c0b517733c..27d3f0e9f68f 100644 --- a/mm/cma.h +++ b/mm/cma.h @@ -2,6 +2,8 @@ #ifndef __MM_CMA_H__ #define __MM_CMA_H__ +#define CMA_MAX_NAME 64 + struct cma { unsigned long base_pfn; unsigned long count; @@ -12,7 +14,7 @@ struct cma { struct hlist_head mem_head; spinlock_t mem_head_lock; #endif - const char *name; + char name[CMA_MAX_NAME]; }; extern struct cma cma_areas[MAX_CMA_AREAS]; -- 2.23.0