From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54659) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gDbXv-0007sO-2I for qemu-devel@nongnu.org; Fri, 19 Oct 2018 16:38:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gDbXu-0002T0-8J for qemu-devel@nongnu.org; Fri, 19 Oct 2018 16:38:59 -0400 From: Liam Merwick Date: Fri, 19 Oct 2018 21:39:01 +0100 Message-Id: <1539981546-10596-4-git-send-email-Liam.Merwick@oracle.com> In-Reply-To: <1539981546-10596-1-git-send-email-Liam.Merwick@oracle.com> References: <1539981546-10596-1-git-send-email-Liam.Merwick@oracle.com> Subject: [Qemu-devel] [PATCH v4 3/8] block: Null pointer dereference in blk_root_get_parent_desc() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, kwolf@redhat.com, jsnow@redhat.com, berrange@redhat.com, mreitz@redhat.com The dev_id returned by the call to blk_get_attached_dev_id() in blk_root_get_parent_desc() can be NULL (an internal call to object_get_canonical_path may have returned NULL). Instead of just checking this case before before dereferencing, adjust blk_get_attached_dev_id() to return the empty string if no object path can be found (similar to the case when blk->dev is NULL and an empty string is returned). Signed-off-by: Liam Merwick --- block/block-backend.c | 6 +++++- dtc | 2 +- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index dc0cd5772413..e628920f3cd8 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -909,6 +909,7 @@ void *blk_get_attached_dev(BlockBackend *blk) char *blk_get_attached_dev_id(BlockBackend *blk) { DeviceState *dev; + char *dev_id; assert(!blk->legacy_dev); dev = blk->dev; @@ -918,7 +919,10 @@ char *blk_get_attached_dev_id(BlockBackend *blk) } else if (dev->id) { return g_strdup(dev->id); } - return object_get_canonical_path(OBJECT(dev)); + + dev_id = object_get_canonical_path(OBJECT(dev)); + + return dev_id ? dev_id : g_strdup(""); } /* diff --git a/dtc b/dtc index 88f18909db73..e54388015af1 160000 --- a/dtc +++ b/dtc @@ -1 +1 @@ -Subproject commit 88f18909db731a627456f26d779445f84e449536 +Subproject commit e54388015af1fb4bf04d0bca99caba1074d9cc42 -- 1.8.3.1