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authorMike Kravetz <mike.kravetz@oracle.com>2019-04-05 18:39:06 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-05-08 07:20:50 +0200
commit250b62d1f0b0cb28ade5a311d5a3727bd0f846df (patch)
tree56c86b1d075d43fdf9da41bf97f21e99018aa095 /fs
parent1b19cbd71eaa65b6df7a2c594baf4f7c25c98f57 (diff)
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hugetlbfs: fix memory leak for resv_map
[ Upstream commit 58b6e5e8f1addd44583d61b0a03c0f5519527e35 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/hugetlbfs/inode.c20
1 files changed, 14 insertions, 6 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index eb6f3de29f69..dd28a9b287da 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -730,11 +730,17 @@ 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) {
@@ -766,8 +772,10 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
break;
}
lockdep_annotate_inode_mutex_key(inode);
- } else
- kref_put(&resv_map->refs, resv_map_release);
+ } else {
+ if (resv_map)
+ kref_put(&resv_map->refs, resv_map_release);
+ }
return inode;
}