This is a note to let you know that I've just added the patch titled
xen-blkback: don't leak persistent grants from xen_blkbk_map()
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xen-blkback-don-t-leak-persistent-grants-from.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b7649f4e1d73402aaf46cb8260df6161b101b593 Mon Sep 17 00:00:00 2001
From: Jan Beulich <jbeulich@xxxxxxxx>
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@xxxxxxxx>
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@xxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Wei Liu <wl@xxxxxxx>
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -919,7 +919,7 @@ 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;
}
Patches currently in stable-queue which might be from jbeulich@xxxxxxxx are
queue-4.4/xen-blkback-don-t-leak-persistent-grants-from.patch
