From a184563778f2b8970eb93291f08108e66432a575 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 10 May 2023 22:35:55 +0200 Subject: [PATCH] block/export: Fix null pointer dereference in error path There are some error paths in blk_exp_add() that jump to 'fail:' before 'exp' is even created. So we can't just unconditionally access exp->blk. Add a NULL check, and switch from exp->blk to blk, which is available earlier, just to be extra sure that we really cover all cases where BlockDevOps could have been set for it (in practice, this only happens in drv->create() today, so this part of the change isn't strictly necessary). Fixes: Coverity CID 1509238 Fixes: de79b52604e43fdeba6cee4f5af600b62169f2d2 Signed-off-by: Kevin Wolf Message-Id: <20230510203601.418015-3-kwolf@redhat.com> Reviewed-by: Eric Blake Tested-by: Eric Blake Signed-off-by: Kevin Wolf --- block/export/export.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/block/export/export.c b/block/export/export.c index 62c7c22d45..a5c8f42f53 100644 --- a/block/export/export.c +++ b/block/export/export.c @@ -192,8 +192,10 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) return exp; fail: - blk_set_dev_ops(exp->blk, NULL, NULL); - blk_unref(blk); + if (blk) { + blk_set_dev_ops(blk, NULL, NULL); + blk_unref(blk); + } aio_context_release(ctx); if (exp) { g_free(exp->id);