Messages in this thread Patch in this message | | | From | Jiasheng Jiang <> | Subject | [PATCH] mm/vmalloc: Add check for KMEM_CACHE | Date | Thu, 24 Nov 2022 12:02:26 +0800 |
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As KMEM_CACHE may return NULL pointer, it should be better to check the return value in order to avoid NULL pointer dereference in kmem_cache_zalloc.
Fixes: 68ad4a330433 ("mm/vmalloc.c: keep track of free blocks for vmap allocation") Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn> --- mm/vmalloc.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index ccaa461998f3..df3e59f614cc 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2426,15 +2426,17 @@ void __init vmalloc_init(void) } /* Import existing vmlist entries. */ - for (tmp = vmlist; tmp; tmp = tmp->next) { - va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); - if (WARN_ON_ONCE(!va)) - continue; + if (!WARN_ON_ONCE(!vmap_area_cachep)) { + for (tmp = vmlist; tmp; tmp = tmp->next) { + va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); + if (WARN_ON_ONCE(!va)) + continue; - va->va_start = (unsigned long)tmp->addr; - va->va_end = va->va_start + tmp->size; - va->vm = tmp; - insert_vmap_area(va, &vmap_area_root, &vmap_area_list); + va->va_start = (unsigned long)tmp->addr; + va->va_end = va->va_start + tmp->size; + va->vm = tmp; + insert_vmap_area(va, &vmap_area_root, &vmap_area_list); + } } /* -- 2.25.1
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