On Fri, Apr 19, 2024 at 6:17 PM <hailong.liu@xxxxxxxx> wrote: > > 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); might be ZERO_SIZE_PTR. > } > order = get_order(size); > > -- > 2.34.1
