projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| 7be4ccde SL |
1 | From 960e849a37e5004b0aadb515457ad68ae7b2f181 Mon Sep 17 00:00:00 2001 |
| 2 | From: Mike Kravetz <mike.kravetz@oracle.com> | |
| 3 | Date: Fri, 5 Apr 2019 18:39:06 -0700 | |
| 4 | Subject: hugetlbfs: fix memory leak for resv_map | |
| 5 | ||
| 6 | [ Upstream commit 58b6e5e8f1addd44583d61b0a03c0f5519527e35 ] | |
| 7 | ||
| 8 | When mknod is used to create a block special file in hugetlbfs, it will | |
| 9 | allocate an inode and kmalloc a 'struct resv_map' via resv_map_alloc(). | |
| 10 | inode->i_mapping->private_data will point the newly allocated resv_map. | |
| 11 | However, when the device special file is opened bd_acquire() will set | |
| 12 | inode->i_mapping to bd_inode->i_mapping. Thus the pointer to the | |
| 13 | allocated resv_map is lost and the structure is leaked. | |
| 14 | ||
| 15 | Programs to reproduce: | |
| 16 | mount -t hugetlbfs nodev hugetlbfs | |
| 17 | mknod hugetlbfs/dev b 0 0 | |
| 18 | exec 30<> hugetlbfs/dev | |
| 19 | umount hugetlbfs/ | |
| 20 | ||
| 21 | resv_map structures are only needed for inodes which can have associated | |
| 22 | page allocations. To fix the leak, only allocate resv_map for those | |
| 23 | inodes which could possibly be associated with page allocations. | |
| 24 | ||
| 25 | Link: http://lkml.kernel.org/r/20190401213101.16476-1-mike.kravetz@oracle.com | |
| 26 | Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> | |
| 27 | Reviewed-by: Andrew Morton <akpm@linux-foundation.org> | |
| 28 | Reported-by: Yufen Yu <yuyufen@huawei.com> | |
| 29 | Suggested-by: Yufen Yu <yuyufen@huawei.com> | |
| 30 | Signed-off-by: Andrew Morton <akpm@linux-foundation.org> | |
| 31 | Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> | |
| 32 | Signed-off-by: Sasha Levin <sashal@kernel.org> | |
| 33 | --- | |
| 34 | fs/hugetlbfs/inode.c | 20 ++++++++++++++------ | |
| 35 | 1 file changed, 14 insertions(+), 6 deletions(-) | |
| 36 | ||
| 37 | diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c | |
| 38 | index a7fa037b876b..a3a3d256fb0e 100644 | |
| 39 | --- a/fs/hugetlbfs/inode.c | |
| 40 | +++ b/fs/hugetlbfs/inode.c | |
| 41 | @@ -741,11 +741,17 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb, | |
| 42 | umode_t mode, dev_t dev) | |
| 43 | { | |
| 44 | struct inode *inode; | |
| 45 | - struct resv_map *resv_map; | |
| 46 | + struct resv_map *resv_map = NULL; | |
| 47 | ||
| 48 | - resv_map = resv_map_alloc(); | |
| 49 | - if (!resv_map) | |
| 50 | - return NULL; | |
| 51 | + /* | |
| 52 | + * Reserve maps are only needed for inodes that can have associated | |
| 53 | + * page allocations. | |
| 54 | + */ | |
| 55 | + if (S_ISREG(mode) || S_ISLNK(mode)) { | |
| 56 | + resv_map = resv_map_alloc(); | |
| 57 | + if (!resv_map) | |
| 58 | + return NULL; | |
| 59 | + } | |
| 60 | ||
| 61 | inode = new_inode(sb); | |
| 62 | if (inode) { | |
| 63 | @@ -780,8 +786,10 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb, | |
| 64 | break; | |
| 65 | } | |
| 66 | lockdep_annotate_inode_mutex_key(inode); | |
| 67 | - } else | |
| 68 | - kref_put(&resv_map->refs, resv_map_release); | |
| 69 | + } else { | |
| 70 | + if (resv_map) | |
| 71 | + kref_put(&resv_map->refs, resv_map_release); | |
| 72 | + } | |
| 73 | ||
| 74 | return inode; | |
| 75 | } | |
| 76 | -- | |
| 77 | 2.20.1 | |
| 78 |