From: Kevin Wolf Date: Wed, 10 May 2023 20:35:55 +0000 (+0200) Subject: block/export: Fix null pointer dereference in error path X-Git-Tag: v8.0.2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=bea933e430249fb81e1c020ddf50511d0481d56e;p=thirdparty%2Fqemu.git 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 (cherry picked from commit a184563778f2b8970eb93291f08108e66432a575) Signed-off-by: Michael Tokarev --- diff --git a/block/export/export.c b/block/export/export.c index cdef2989027..33f8f8ffa43 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);