| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 213/241] CIFS: cifs_read_allocate_pages: dont iterate through whole page array on ENOMEM | Date | Sun, 9 Jun 2019 18:42:35 +0200 |
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From: Roberto Bergantinos Corpas <rbergant@redhat.com>
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>
--- fs/cifs/file.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2829,7 +2829,9 @@ cifs_read_allocate_pages(struct cifs_rea } 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; }
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