Use __GFP_NO_OBJ_EXT to prevent recursions when allocating slabobj_ext objects. Also prevent slabobj_ext allocations for kmem_cache objects.
Signed-off-by: Suren Baghdasaryan <[email protected]> --- mm/slab.h | 6 ++++++ mm/slab_common.c | 2 ++ 2 files changed, 8 insertions(+) diff --git a/mm/slab.h b/mm/slab.h index 436a126486b5..f4ff635091e4 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -589,6 +589,12 @@ prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p) if (!need_slab_obj_ext()) return NULL; + if (s->flags & SLAB_NO_OBJ_EXT) + return NULL; + + if (flags & __GFP_NO_OBJ_EXT) + return NULL; + slab = virt_to_slab(p); if (!slab_obj_exts(slab) && WARN(alloc_slab_obj_exts(slab, s, flags, false), diff --git a/mm/slab_common.c b/mm/slab_common.c index 6bfa1810da5e..83fec2dd2e2d 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -218,6 +218,8 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, void *vec; gfp &= ~OBJCGS_CLEAR_MASK; + /* Prevent recursive extension vector allocation */ + gfp |= __GFP_NO_OBJ_EXT; vec = kcalloc_node(objects, sizeof(struct slabobj_ext), gfp, slab_nid(slab)); if (!vec) -- 2.43.0.687.g38aa6559b0-goog
