Commit f1659e5b authored by Jan Beulich's avatar Jan Beulich Committed by Zheng Zengkai
Browse files

xen-blkback: don't leak persistent grants from xen_blkbk_map() 



stable inclusion
from stable-5.10.27
commit 3a1ca9bd4f5a647439e82e07b03d072781d9d180
bugzilla: 51493

--------------------------------

commit a846738f 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: default avatarJan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarWei Liu <wl@xen.org>
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarChen Jun <chenjun102@huawei.com>
Acked-by: default avatar&nbsp; Weilong Chen <chenweilong@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 1d187720

drivers/block/xen-blkback/blkback.c

+1 −1
Original line number Diff line number Diff line
@@ -891,7 +891,7 @@ static int xen_blkbk_map(struct xen_blkif_ring *ring, 
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;

	}