| From b7649f4e1d73402aaf46cb8260df6161b101b593 Mon Sep 17 00:00:00 2001 |
| From: Jan Beulich <jbeulich@suse.com> |
| Date: Fri, 26 Mar 2021 16:28:57 +0100 |
| Subject: xen-blkback: don't leak persistent grants from xen_blkbk_map() |
| |
| From: Jan Beulich <jbeulich@suse.com> |
| |
| commit a846738f8c3788d846ed1f587270d2f2e3d32432 upstream. |
| |
| The fix for XSA-365 zapped too many of the ->persistent_gnt[] entries. |
| Ones successfully obtained should not be overwritten, but instead left |
| for xen_blkbk_unmap_prepare() to pick up and put. |
| |
| This is XSA-371. |
| |
| Signed-off-by: Jan Beulich <jbeulich@suse.com> |
| Cc: stable@vger.kernel.org |
| Reviewed-by: Juergen Gross <jgross@suse.com> |
| Reviewed-by: Wei Liu <wl@xen.org> |
| Signed-off-by: Juergen Gross <jgross@suse.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/block/xen-blkback/blkback.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/drivers/block/xen-blkback/blkback.c |
| +++ b/drivers/block/xen-blkback/blkback.c |
| @@ -944,7 +944,7 @@ next: |
| out: |
| for (i = last_map; i < num; i++) { |
| /* Don't zap current batch's valid persistent grants. */ |
| - if(i >= last_map + segs_to_map) |
| + if(i >= map_until) |
| pages[i]->persistent_gnt = NULL; |
| pages[i]->handle = BLKBACK_INVALID_HANDLE; |
| } |
