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authorTrond Myklebust <trondmy@gmail.com>2020-02-02 17:53:53 -0500
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2020-02-03 16:35:17 -0500
commit4b310319c6a8ce708f1033d57145e2aa027a883c (patch)
tree8c829779d65e9f3cda6bbbc85671e176df20f06f /fs/nfs/dir.c
parent7ccbddbe3e67591a02ddd20078d1241bd8fe79f3 (diff)
NFS: Fix memory leaks and corruption in readdir
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>
Diffstat (limited to 'fs/nfs/dir.c')
-rw-r--r--fs/nfs/dir.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 6427a8a8d61a..451c48cdb1c2 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -162,6 +162,17 @@ typedef struct {
bool eof;
} 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()
*/
@@ -174,6 +185,7 @@ 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);
}
@@ -610,6 +622,8 @@ 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;
@@ -626,8 +640,6 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
}
array = kmap(page);
- memset(array, 0, sizeof(struct nfs_cache_array));
- array->eof_index = -1;
status = nfs_readdir_alloc_pages(pages, array_size);
if (status < 0)
@@ -682,6 +694,7 @@ int nfs_readdir_filler(void *data, struct page* page)
unlock_page(page);
return 0;
error:
+ nfs_readdir_clear_array(page);
unlock_page(page);
return ret;
}