CIFS: cifs_read_allocate_pages: don't iterate through whole page array on ENOMEM
commit 31fad7d41e73731f05b8053d17078638cf850fa6 upstream.
In cifs_read_allocate_pages, in case of ENOMEM, we go through
whole rdata->pages array but we have failed the allocation before
nr_pages, therefore we may end up calling put_page with NULL
pointer, causing oops
Signed-off-by: Roberto Bergantinos Corpas <rbergant@redhat.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index e7f1773..df3ee0b 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2892,7 +2892,9 @@
}
if (rc) {
- for (i = 0; i < nr_pages; i++) {
+ unsigned int nr_page_failed = i;
+
+ for (i = 0; i < nr_page_failed; i++) {
put_page(rdata->pages[i]);
rdata->pages[i] = NULL;
}