| Message ID | cd825aa4897b0fc37d3316838993881daccbe9f5.1549921721.git.andreyknvl@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kasan: more tag based mode fixes | expand |
On 11/02/2019 21:59, Andrey Konovalov wrote: > Right now we call kmemleak hooks before assigning tags to pointers in > KASAN hooks. As a result, when an objects gets allocated, kmemleak sees > a differently tagged pointer, compared to the one it sees when the object > gets freed. Fix it by calling KASAN hooks before kmemleak's ones. > Nit: Could you please add comments to the the code? It should prevent that the code gets refactored in future, reintroducing the same issue. > Reported-by: Qian Cai <cai@lca.pw> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> > --- > mm/slab.h | 6 ++---- > mm/slab_common.c | 2 +- > mm/slub.c | 3 ++- > 3 files changed, 5 insertions(+), 6 deletions(-) > > diff --git a/mm/slab.h b/mm/slab.h > index 4190c24ef0e9..638ea1b25d39 100644 > --- a/mm/slab.h > +++ b/mm/slab.h > @@ -437,11 +437,9 @@ static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, > > flags &= gfp_allowed_mask; > for (i = 0; i < size; i++) { > - void *object = p[i]; > - > - kmemleak_alloc_recursive(object, s->object_size, 1, > + p[i] = kasan_slab_alloc(s, p[i], flags); > + kmemleak_alloc_recursive(p[i], s->object_size, 1, > s->flags, flags); > - p[i] = kasan_slab_alloc(s, object, flags); > } > > if (memcg_kmem_enabled()) > diff --git a/mm/slab_common.c b/mm/slab_common.c > index 81732d05e74a..fe524c8d0246 100644 > --- a/mm/slab_common.c > +++ b/mm/slab_common.c > @@ -1228,8 +1228,8 @@ void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) > flags |= __GFP_COMP; > page = alloc_pages(flags, order); > ret = page ? page_address(page) : NULL; > - kmemleak_alloc(ret, size, 1, flags); > ret = kasan_kmalloc_large(ret, size, flags); > + kmemleak_alloc(ret, size, 1, flags); > return ret; > } > EXPORT_SYMBOL(kmalloc_order); > diff --git a/mm/slub.c b/mm/slub.c > index 1e3d0ec4e200..4a3d7686902f 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -1374,8 +1374,9 @@ static inline void dec_slabs_node(struct kmem_cache *s, int node, > */ > static inline void *kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags) > { > + ptr = kasan_kmalloc_large(ptr, size, flags); > kmemleak_alloc(ptr, size, 1, flags); > - return kasan_kmalloc_large(ptr, size, flags); > + return ptr; > } > > static __always_inline void kfree_hook(void *x) >
On Tue, Feb 12, 2019 at 4:57 PM Vincenzo Frascino <vincenzo.frascino@arm.com> wrote: > > On 11/02/2019 21:59, Andrey Konovalov wrote: > > Right now we call kmemleak hooks before assigning tags to pointers in > > KASAN hooks. As a result, when an objects gets allocated, kmemleak sees > > a differently tagged pointer, compared to the one it sees when the object > > gets freed. Fix it by calling KASAN hooks before kmemleak's ones. > > > > Nit: Could you please add comments to the the code? It should prevent that the > code gets refactored in future, reintroducing the same issue. Sure, I'll send v2 with comments, thanks! > > > Reported-by: Qian Cai <cai@lca.pw> > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> > > --- > > mm/slab.h | 6 ++---- > > mm/slab_common.c | 2 +- > > mm/slub.c | 3 ++- > > 3 files changed, 5 insertions(+), 6 deletions(-) > > > > diff --git a/mm/slab.h b/mm/slab.h > > index 4190c24ef0e9..638ea1b25d39 100644 > > --- a/mm/slab.h > > +++ b/mm/slab.h > > @@ -437,11 +437,9 @@ static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, > > > > flags &= gfp_allowed_mask; > > for (i = 0; i < size; i++) { > > - void *object = p[i]; > > - > > - kmemleak_alloc_recursive(object, s->object_size, 1, > > + p[i] = kasan_slab_alloc(s, p[i], flags); > > + kmemleak_alloc_recursive(p[i], s->object_size, 1, > > s->flags, flags); > > - p[i] = kasan_slab_alloc(s, object, flags); > > } > > > > if (memcg_kmem_enabled()) > > diff --git a/mm/slab_common.c b/mm/slab_common.c > > index 81732d05e74a..fe524c8d0246 100644 > > --- a/mm/slab_common.c > > +++ b/mm/slab_common.c > > @@ -1228,8 +1228,8 @@ void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) > > flags |= __GFP_COMP; > > page = alloc_pages(flags, order); > > ret = page ? page_address(page) : NULL; > > - kmemleak_alloc(ret, size, 1, flags); > > ret = kasan_kmalloc_large(ret, size, flags); > > + kmemleak_alloc(ret, size, 1, flags); > > return ret; > > } > > EXPORT_SYMBOL(kmalloc_order); > > diff --git a/mm/slub.c b/mm/slub.c > > index 1e3d0ec4e200..4a3d7686902f 100644 > > --- a/mm/slub.c > > +++ b/mm/slub.c > > @@ -1374,8 +1374,9 @@ static inline void dec_slabs_node(struct kmem_cache *s, int node, > > */ > > static inline void *kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags) > > { > > + ptr = kasan_kmalloc_large(ptr, size, flags); > > kmemleak_alloc(ptr, size, 1, flags); > > - return kasan_kmalloc_large(ptr, size, flags); > > + return ptr; > > } > > > > static __always_inline void kfree_hook(void *x) > > > > -- > Regards, > Vincenzo > > -- > You received this message because you are subscribed to the Google Groups "kasan-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@googlegroups.com. > To post to this group, send email to kasan-dev@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/f57831be-c57a-4a9e-992e-1f193866467b%40arm.com. > For more options, visit https://groups.google.com/d/optout.
diff --git a/mm/slab.h b/mm/slab.h index 4190c24ef0e9..638ea1b25d39 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -437,11 +437,9 @@ static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, flags &= gfp_allowed_mask; for (i = 0; i < size; i++) { - void *object = p[i]; - - kmemleak_alloc_recursive(object, s->object_size, 1, + p[i] = kasan_slab_alloc(s, p[i], flags); + kmemleak_alloc_recursive(p[i], s->object_size, 1, s->flags, flags); - p[i] = kasan_slab_alloc(s, object, flags); } if (memcg_kmem_enabled()) diff --git a/mm/slab_common.c b/mm/slab_common.c index 81732d05e74a..fe524c8d0246 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -1228,8 +1228,8 @@ void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) flags |= __GFP_COMP; page = alloc_pages(flags, order); ret = page ? page_address(page) : NULL; - kmemleak_alloc(ret, size, 1, flags); ret = kasan_kmalloc_large(ret, size, flags); + kmemleak_alloc(ret, size, 1, flags); return ret; } EXPORT_SYMBOL(kmalloc_order); diff --git a/mm/slub.c b/mm/slub.c index 1e3d0ec4e200..4a3d7686902f 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1374,8 +1374,9 @@ static inline void dec_slabs_node(struct kmem_cache *s, int node, */ static inline void *kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags) { + ptr = kasan_kmalloc_large(ptr, size, flags); kmemleak_alloc(ptr, size, 1, flags); - return kasan_kmalloc_large(ptr, size, flags); + return ptr; } static __always_inline void kfree_hook(void *x)
Right now we call kmemleak hooks before assigning tags to pointers in KASAN hooks. As a result, when an objects gets allocated, kmemleak sees a differently tagged pointer, compared to the one it sees when the object gets freed. Fix it by calling KASAN hooks before kmemleak's ones. Reported-by: Qian Cai <cai@lca.pw> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> --- mm/slab.h | 6 ++---- mm/slab_common.c | 2 +- mm/slub.c | 3 ++- 3 files changed, 5 insertions(+), 6 deletions(-)