From: Jan Beulich Date: Mon, 15 Feb 2021 07:54:51 +0000 (+0100) Subject: xen-blkback: don't "handle" error by BUG() X-Git-Tag: v4.4.258~6 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=74e38b7a6972fd6983e6fbd929b65746ce975aed;p=thirdparty%2Fkernel%2Fstable.git xen-blkback: don't "handle" error by BUG() commit 5a264285ed1cd32e26d9de4f3c8c6855e467fd63 upstream. In particular -ENOMEM may come back here, from set_foreign_p2m_mapping(). Don't make problems worse, the more that handling elsewhere (together with map's status fields now indicating whether a mapping wasn't even attempted, and hence has to be considered failed) doesn't require this odd way of dealing with errors. This is part of XSA-362. Signed-off-by: Jan Beulich Cc: stable@vger.kernel.org Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index 8dbdd156e0d3e..3e84d59724a2d 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -842,10 +842,8 @@ again: break; } - if (segs_to_map) { + if (segs_to_map) ret = gnttab_map_refs(map, NULL, pages_to_gnt, segs_to_map); - BUG_ON(ret); - } /* * Now swizzle the MFN in our domain with the MFN from the other domain @@ -860,7 +858,7 @@ again: pr_debug("invalid buffer -- could not remap it\n"); put_free_pages(blkif, &pages[seg_idx]->page, 1); pages[seg_idx]->handle = BLKBACK_INVALID_HANDLE; - ret |= 1; + ret |= !ret; goto next; } pages[seg_idx]->handle = map[new_map_idx].handle;