From 773686b4fcda58779d4c6d5655c84e8aa15c58c5 Mon Sep 17 00:00:00 2001 From: Ross Lagerwall Date: Tue, 14 Apr 2020 15:20:48 +0200 Subject: [PATCH] xen/gnttab: Fix error path in map_grant_ref() Part of XSA-295 (c/s 863e74eb2cffb) inadvertently re-positioned the brackets, changing the logic. If the _set_status() call fails, the grant_map hypercall would fail with a status of 1 (rc != GNTST_okay) instead of the expected negative GNTST_* error. This error path can be taken due to bad guest state, and causes net/blk-back in Linux to crash. This is XSA-316. Signed-off-by: Ross Lagerwall Reviewed-by: Andrew Cooper Reviewed-by: Julien Grall master commit: da0c66c8f48042a0186799014af69db0303b1da5 master date: 2020-04-14 14:41:02 +0200 --- xen/common/grant_table.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c index 1e72397ee4..3027478e30 100644 --- a/xen/common/grant_table.c +++ b/xen/common/grant_table.c @@ -890,7 +890,7 @@ __gnttab_map_grant_ref( { if ( (rc = _set_status(shah, status, rd, rgt->gt_version, act, op->flags & GNTMAP_readonly, 1, - ld->domain_id) != GNTST_okay) ) + ld->domain_id)) != GNTST_okay ) goto act_release_out; if ( !act->pin ) -- 2.39.5