Skip to content
Commit 58b6e5e8 authored by Mike Kravetz's avatar Mike Kravetz Committed by Linus Torvalds
Browse files

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: default avatarMike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reported-by: default avatarYufen Yu <yuyufen@huawei.com>
Suggested-by: default avatarYufen Yu <yuyufen@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent fcae96ff
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment