3.16.84-rc1 review patch. If anyone has any objections, please let me know.
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From: Trond Myklebust trondmy@gmail.com
commit 4b310319c6a8ce708f1033d57145e2aa027a883c upstream.
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") 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: Ben Hutchings ben@decadent.org.uk --- fs/nfs/dir.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-)
--- 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); +} + /* * we are freeing strings created by nfs_add_to_readdir_array() */ @@ -181,6 +192,7 @@ void nfs_readdir_clear_array(struct page array = kmap_atomic(page); for (i = 0; i < array->size; i++) kfree(array->array[i].string.name); + array->size = 0; kunmap_atomic(array); }
@@ -580,6 +592,8 @@ int nfs_readdir_xdr_to_array(nfs_readdir 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; @@ -596,8 +610,6 @@ int nfs_readdir_xdr_to_array(nfs_readdir }
array = kmap(page); - memset(array, 0, sizeof(struct nfs_cache_array)); - array->eof_index = -1;
status = nfs_readdir_large_page(pages, array_size); if (status < 0) @@ -651,6 +663,7 @@ int nfs_readdir_filler(nfs_readdir_descr unlock_page(page); return 0; error: + nfs_readdir_clear_array(page); unlock_page(page); return ret; }