From: "Hailong.Liu" <hailong.liu@xxxxxxxx> vm_map_ram check return value of vb_alloc by IS_ERR. if vm_map_ram(page, 0, 0) , vb_alloc(0, GFP_KERNEL) would return NULL which cause kernel panic by vmap_pages_range_noflush。fix this by return ERR_PTR(-EINVAL) if size is 0. Signed-off-by: Hailong.Liu <hailong.liu@xxxxxxxx> --- Changes since v1 [1]: - Return ERR_PTR(-EINVAL) or not check IS_ERR_OR_NULL BTW, Barry suggests me that if count is 0, return directly, in my opinion, change return value is more resonable. [1] https://lore.kernel.org/all/84d7cd03-1cf8-401a-8edf-2524db0bd6d5@xxxxxxxx/ mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index a3fedb3ee0db..c430a999805b 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2173,7 +2173,7 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask) * get_order(0) returns funny result. Just warn and terminate * early. */ - return NULL; + return ERR_PTR(-EINVAL); } order = get_order(size); -- 2.34.1
