path: root/fs
diff options
authorMike Kravetz <mike.kravetz@oracle.com>2019-04-05 18:39:06 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-04-05 16:02:31 -1000
commit58b6e5e8f1addd44583d61b0a03c0f5519527e35 (patch)
tree26842d20ba459c65b3345d36d93aab955d63a2af /fs
parentfcae96ff96538f66e7acd5d4e0f2e7516ff8cbd0 (diff)
hugetlbfs: fix memory leak for resv_map
When mknod is used to create a block special file in hugetlbfs, it will allocate an inode and kmalloc a 'struct resv_map' via resv_map_alloc(). inode->i_mapping->private_data will point the newly allocated resv_map. However, when the device special file is opened bd_acquire() will set inode->i_mapping to bd_inode->i_mapping. Thus the pointer to the allocated resv_map is lost and the structure is leaked. Programs to reproduce: mount -t hugetlbfs nodev hugetlbfs mknod hugetlbfs/dev b 0 0 exec 30<> hugetlbfs/dev umount hugetlbfs/ resv_map structures are only needed for inodes which can have associated page allocations. To fix the leak, only allocate resv_map for those inodes which could possibly be associated with page allocations. Link: http://lkml.kernel.org/r/20190401213101.16476-1-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reported-by: Yufen Yu <yuyufen@huawei.com> Suggested-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
1 files changed, 14 insertions, 6 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index ec32fece5e1e..9285dd4f4b1c 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -755,11 +755,17 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
umode_t mode, dev_t dev)
struct inode *inode;
- struct resv_map *resv_map;
+ struct resv_map *resv_map = NULL;
- resv_map = resv_map_alloc();
- if (!resv_map)
- return NULL;
+ /*
+ * Reserve maps are only needed for inodes that can have associated
+ * page allocations.
+ */
+ if (S_ISREG(mode) || S_ISLNK(mode)) {
+ resv_map = resv_map_alloc();
+ if (!resv_map)
+ return NULL;
+ }
inode = new_inode(sb);
if (inode) {
@@ -794,8 +800,10 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
- } else
- kref_put(&resv_map->refs, resv_map_release);
+ } else {
+ if (resv_map)
+ kref_put(&resv_map->refs, resv_map_release);
+ }
return inode;