{"id":2222709,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2222709/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260413214549.926435-4-junjie.cao@intel.com/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/1.1/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20260413214549.926435-4-junjie.cao@intel.com>","date":"2026-04-13T21:45:48","name":"[v3,3/4] migration/file: fix type mismatch and NULL deref in multifd_file_recv_data","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"cab439379d07cdfb6d7f13ba6e02db5c52239260","submitter":{"id":91537,"url":"http://patchwork.ozlabs.org/api/1.1/people/91537/?format=json","name":"Junjie Cao","email":"junjie.cao@intel.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260413214549.926435-4-junjie.cao@intel.com/mbox/","series":[{"id":499708,"url":"http://patchwork.ozlabs.org/api/1.1/series/499708/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=499708","date":"2026-04-13T21:45:46","name":"io/channel: complete pread/pwrite_all API and fix multifd_file_recv_data","version":3,"mbox":"http://patchwork.ozlabs.org/series/499708/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2222709/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2222709/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256\n header.s=Intel header.b=JuPavCBX;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; 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Mon, 13 Apr 2026 09:46:32 -0400","from orviesa005.jf.intel.com ([10.64.159.145])\n by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384;\n 13 Apr 2026 06:46:30 -0700","from junjie-optiplex-micro-plus-7010.bj.intel.com ([10.238.152.98])\n by orviesa005-auth.jf.intel.com with\n ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Apr 2026 06:46:29 -0700"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple;\n d=intel.com; i=@intel.com; q=dns/txt; s=Intel;\n t=1776087992; x=1807623992;\n h=from:to:cc:subject:date:message-id:in-reply-to:\n references:mime-version:content-transfer-encoding;\n bh=jRIYr/DJPikQoTUtLLf24NEzeIOFia6aU6GKa/BmoKA=;\n b=JuPavCBXydKLribUPiYNn7ONXxn6tvNffsOv1MzoYyZdX+uIPCFWBHq6\n a7QcWHekemdFdKBsBUtnkQbYtMvVAtw4yXW/UuLU+DlzBv7ahdBi3AMev\n cVgxd2Gm3+uLfAUHIjREqucHL2keofRuiS0V/DMBliHrZeMIBqjGC/gaI\n UvED3JHS5YWSjrOwmXRiqM7TgElYr6s0XhIcKVIA+IWps4SiVPN/XcF8o\n FsGEjAgw3eDyqgx/ZMHNzG0KhnPR/ZBaZVnI1KKXv7O+Dcl77g52TNsFD\n fWjV2vhHjwMrNWfNJKEV0RLZq9Zvtyneeq198rc8uMh8LDIMCqjiZ9sIu Q==;","X-CSE-ConnectionGUID":["HFgKHtr+TIC+F5/5Z6eEiA==","mRaTV8cTR++7NbeU2U3tEA=="],"X-CSE-MsgGUID":["8M0HvRKgSwqlJyA52+tIxw==","ffP93G3MQ9SAB2yOrdMGKw=="],"X-IronPort-AV":["E=McAfee;i=\"6800,10657,11758\"; a=\"80885675\"","E=Sophos;i=\"6.23,177,1770624000\"; d=\"scan'208\";a=\"80885675\"","E=Sophos;i=\"6.23,177,1770624000\"; d=\"scan'208\";a=\"234770429\""],"X-ExtLoop1":"1","From":"Junjie Cao ","To":"qemu-devel@nongnu.org","Cc":"berrange@redhat.com, peterx@redhat.com, farosas@suse.de,\n junjie.cao@intel.com","Subject":"[PATCH v3 3/4] migration/file: fix type mismatch and NULL deref in\n multifd_file_recv_data","Date":"Tue, 14 Apr 2026 05:45:48 +0800","Message-ID":"<20260413214549.926435-4-junjie.cao@intel.com>","X-Mailer":"git-send-email 2.43.0","In-Reply-To":"<20260413214549.926435-1-junjie.cao@intel.com>","References":"<20260413214549.926435-1-junjie.cao@intel.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=UTF-8","Content-Transfer-Encoding":"8bit","Received-SPF":"pass client-ip=198.175.65.14;\n envelope-from=junjie.cao@intel.com;\n helo=mgamail.intel.com","X-Spam_score_int":"-29","X-Spam_score":"-3.0","X-Spam_bar":"---","X-Spam_report":"(-3.0 / 5.0 requ) BAYES_00=-1.9, DATE_IN_FUTURE_06_12=1.947,\n DKIMWL_WL_HIGH=-0.54, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1,\n DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3,\n RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001,\n SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no","X-Spam_action":"no action","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"qemu development ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"multifd_file_recv_data() stores the return value of qio_channel_pread()\n(ssize_t) in a size_t variable. On I/O error the -1 return value wraps\nto SIZE_MAX, producing a nonsensical read size in the error message.\n\nMore critically, a short read (0 <= ret < data->size) is possible when\nthe migration file is truncated. In that case qio_channel_pread()\nreturns a non-negative value without setting *errp. The function then\ncalls error_prepend(errp, ...) which dereferences *errp -- a NULL\npointer -- crashing QEMU.\n\nFix both issues by switching to qio_channel_pread_all() introduced in\na previous patch, which retries on short reads and treats end-of-file\nas an error, so the caller no longer needs to check the byte count\nmanually. Add ERRP_GUARD() so that error_prepend() works correctly\neven when errp is &error_fatal or NULL.\n\nFixes: a49d15a38d3d (\"migration/multifd: Support incoming mapped-ram stream format\")\nSuggested-by: Peter Xu \nReviewed-by: Daniel P. Berrangé \nSigned-off-by: Junjie Cao \n---\n migration/file.c | 13 +++++++------\n 1 file changed, 7 insertions(+), 6 deletions(-)","diff":"diff --git a/migration/file.c b/migration/file.c\nindex 5618aced49..0853188601 100644\n--- a/migration/file.c\n+++ b/migration/file.c\n@@ -254,15 +254,16 @@ int file_write_ramblock_iov(QIOChannel *ioc, const struct iovec *iov,\n \n int multifd_file_recv_data(MultiFDRecvParams *p, Error **errp)\n {\n+ ERRP_GUARD();\n MultiFDRecvData *data = p->data;\n- size_t ret;\n+ int ret;\n \n- ret = qio_channel_pread(p->c, (char *) data->opaque,\n- data->size, data->file_offset, errp);\n- if (ret != data->size) {\n+ ret = qio_channel_pread_all(p->c, (char *) data->opaque,\n+ data->size, data->file_offset, errp);\n+ if (ret != 0) {\n error_prepend(errp,\n- \"multifd recv (%u): read 0x%zx, expected 0x%zx\",\n- p->id, ret, data->size);\n+ \"multifd recv (%u): \",\n+ p->id);\n return -1;\n }\n \n","prefixes":["v3","3/4"]}