From: Trond Myklebust trondmy@gmail.com
[ Upstream commit 4b310319c6a8ce708f1033d57145e2aa027a883c ]
nfs_readdir_xdr_to_array() must not exit without having initialised the array, so that the page cache deletion routines can safely call nfs_readdir_clear_array(). Furthermore, we should ensure that if we exit nfs_readdir_filler() with an error, we free up any page contents to prevent a leak if we try to fill the page again.
Fixes: 11de3b11e08c ("NFS: Fix a memory leak in nfs_readdir") Cc: stable@vger.kernel.org # v2.6.37+ Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Reviewed-by: Benjamin Coddington bcodding@redhat.com Signed-off-by: Anna Schumaker Anna.Schumaker@Netapp.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfs/dir.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index a41df7d44bd7a..5936c54ac5fdb 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -169,6 +169,17 @@ typedef struct { unsigned int eof:1; } nfs_readdir_descriptor_t;
+static +void nfs_readdir_init_array(struct page *page) +{ + struct nfs_cache_array *array; + + array = kmap_atomic(page); + memset(array, 0, sizeof(struct nfs_cache_array)); + array->eof_index = -1; + kunmap_atomic(array); +} + /* * The caller is responsible for calling nfs_readdir_release_array(page) */ @@ -202,6 +213,7 @@ void nfs_readdir_clear_array(struct page *page) array = kmap_atomic(page); for (i = 0; i < array->size; i++) kfree(array->array[i].string.name); + array->size = 0; kunmap_atomic(array); }
@@ -643,6 +655,8 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, int status = -ENOMEM; unsigned int array_size = ARRAY_SIZE(pages);
+ nfs_readdir_init_array(page); + entry.prev_cookie = 0; entry.cookie = desc->last_cookie; entry.eof = 0; @@ -663,8 +677,8 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, status = PTR_ERR(array); goto out_label_free; } - memset(array, 0, sizeof(struct nfs_cache_array)); - array->eof_index = -1; + + array = kmap(page);
status = nfs_readdir_alloc_pages(pages, array_size); if (status < 0) @@ -719,6 +733,7 @@ int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page) unlock_page(page); return 0; error: + nfs_readdir_clear_array(page); unlock_page(page); return ret; }