| Message ID | 20210916123920.48704-2-linmiaohe@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Fixups for slub | expand |
On 9/16/21 14:39, Miaohe Lin wrote: > It's possible that __seq_open_private() will return NULL. So we should > check t before using lest dereferencing NULL pointer. And in error paths, > we forgot to release private buffer via seq_release_private(). Memory > will leak in these paths. > > Fixes: 64dd68497be7 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs") > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> > --- > mm/slub.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/mm/slub.c b/mm/slub.c > index 3d2025f7163b..ed160b6c54f8 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -6108,9 +6108,14 @@ static int slab_debug_trace_open(struct inode *inode, struct file *filep) > struct kmem_cache *s = file_inode(filep)->i_private; > unsigned long *obj_map; > > + if (!t) > + return -ENOMEM; > + > obj_map = bitmap_alloc(oo_objects(s->oo), GFP_KERNEL); > - if (!obj_map) > + if (!obj_map) { > + seq_release_private(inode, filep); > return -ENOMEM; > + } > > if (strcmp(filep->f_path.dentry->d_name.name, "alloc_traces") == 0) > alloc = TRACK_ALLOC; > @@ -6119,6 +6124,7 @@ static int slab_debug_trace_open(struct inode *inode, struct file *filep) > > if (!alloc_loc_track(t, PAGE_SIZE / sizeof(struct location), GFP_KERNEL)) { > bitmap_free(obj_map); > + seq_release_private(inode, filep); > return -ENOMEM; > } > >
diff --git a/mm/slub.c b/mm/slub.c index 3d2025f7163b..ed160b6c54f8 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -6108,9 +6108,14 @@ static int slab_debug_trace_open(struct inode *inode, struct file *filep) struct kmem_cache *s = file_inode(filep)->i_private; unsigned long *obj_map; + if (!t) + return -ENOMEM; + obj_map = bitmap_alloc(oo_objects(s->oo), GFP_KERNEL); - if (!obj_map) + if (!obj_map) { + seq_release_private(inode, filep); return -ENOMEM; + } if (strcmp(filep->f_path.dentry->d_name.name, "alloc_traces") == 0) alloc = TRACK_ALLOC; @@ -6119,6 +6124,7 @@ static int slab_debug_trace_open(struct inode *inode, struct file *filep) if (!alloc_loc_track(t, PAGE_SIZE / sizeof(struct location), GFP_KERNEL)) { bitmap_free(obj_map); + seq_release_private(inode, filep); return -ENOMEM; }
It's possible that __seq_open_private() will return NULL. So we should check t before using lest dereferencing NULL pointer. And in error paths, we forgot to release private buffer via seq_release_private(). Memory will leak in these paths. Fixes: 64dd68497be7 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- mm/slub.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)