From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6A13B13C660; Thu, 13 Jun 2024 12:04:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718280285; cv=none; b=G+HNHr6K77+DugTUP/tbCj9/qIS0cLMj76dTZaQ4W0VBozaWI0KSEGlJjA6pDF6VlXB8hBLoedX7DGO1HaEfkz9aZjltYeUZ/9DhmuOltBV7iblVcrA0Hyyt67Gcnlb3X5P7Q+7l5MMIK0AzqSSPXOkg7h9GYuCoOVKPZMZqpbA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718280285; c=relaxed/simple; bh=Db/CbTG4uvisEV1tR2H+TcxGs+JDzEZtBS6ZhSiZ6bY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UtcRQzo3bkx6OfJ6JrrXH5pyJDnTfsw1E3BrqkFSlmzw53QdGL+TsSYdBuDRExtK1nXqZh1s8bEmYeu4GYZzXRk1yI00Z4iyMprjlUnwh4aboBvhD0pCAsNMvjAPTo54bWL5UjVORBP98gmxDcQIFkr3Sf2SdyhsBzJgSI3bu5w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Oe3BkYNI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Oe3BkYNI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 874D3C2BBFC; Thu, 13 Jun 2024 12:04:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718280284; bh=Db/CbTG4uvisEV1tR2H+TcxGs+JDzEZtBS6ZhSiZ6bY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Oe3BkYNIusBo31HSA4nESxpau+w826gGsj6wPYzh5G7IDktn4ZX0pt9W2eb3zAKC/ 8Ldry0hzfl6WoCj5lhbbNaPOK5+wLrWLkOoWOL85ouJvXK6NvmyEhp/yf/Cj9Ox6Gh qrxohvc9IGcuy+WWxROdh2EIDb0Ru48uvZ9e5yYU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nikita Zhandarovich , Christian Schoenebeck , Dominique Martinet , syzbot+ff14db38f56329ef68df@syzkaller.appspotmail.com Subject: [PATCH 5.4 189/202] net/9p: fix uninit-value in p9_client_rpc() Date: Thu, 13 Jun 2024 13:34:47 +0200 Message-ID: <20240613113235.034416277@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240613113227.759341286@linuxfoundation.org> References: <20240613113227.759341286@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nikita Zhandarovich commit 25460d6f39024cc3b8241b14c7ccf0d6f11a736a upstream. Syzbot with the help of KMSAN reported the following error: BUG: KMSAN: uninit-value in trace_9p_client_res include/trace/events/9p.h:146 [inline] BUG: KMSAN: uninit-value in p9_client_rpc+0x1314/0x1340 net/9p/client.c:754 trace_9p_client_res include/trace/events/9p.h:146 [inline] p9_client_rpc+0x1314/0x1340 net/9p/client.c:754 p9_client_create+0x1551/0x1ff0 net/9p/client.c:1031 v9fs_session_init+0x1b9/0x28e0 fs/9p/v9fs.c:410 v9fs_mount+0xe2/0x12b0 fs/9p/vfs_super.c:122 legacy_get_tree+0x114/0x290 fs/fs_context.c:662 vfs_get_tree+0xa7/0x570 fs/super.c:1797 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352 path_mount+0x742/0x1f20 fs/namespace.c:3679 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x725/0x810 fs/namespace.c:3875 __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Uninit was created at: __alloc_pages+0x9d6/0xe70 mm/page_alloc.c:4598 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2175 [inline] allocate_slab mm/slub.c:2338 [inline] new_slab+0x2de/0x1400 mm/slub.c:2391 ___slab_alloc+0x1184/0x33d0 mm/slub.c:3525 __slab_alloc mm/slub.c:3610 [inline] __slab_alloc_node mm/slub.c:3663 [inline] slab_alloc_node mm/slub.c:3835 [inline] kmem_cache_alloc+0x6d3/0xbe0 mm/slub.c:3852 p9_tag_alloc net/9p/client.c:278 [inline] p9_client_prepare_req+0x20a/0x1770 net/9p/client.c:641 p9_client_rpc+0x27e/0x1340 net/9p/client.c:688 p9_client_create+0x1551/0x1ff0 net/9p/client.c:1031 v9fs_session_init+0x1b9/0x28e0 fs/9p/v9fs.c:410 v9fs_mount+0xe2/0x12b0 fs/9p/vfs_super.c:122 legacy_get_tree+0x114/0x290 fs/fs_context.c:662 vfs_get_tree+0xa7/0x570 fs/super.c:1797 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352 path_mount+0x742/0x1f20 fs/namespace.c:3679 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x725/0x810 fs/namespace.c:3875 __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 If p9_check_errors() fails early in p9_client_rpc(), req->rc.tag will not be properly initialized. However, trace_9p_client_res() ends up trying to print it out anyway before p9_client_rpc() finishes. Fix this issue by assigning default values to p9_fcall fields such as 'tag' and (just in case KMSAN unearths something new) 'id' during the tag allocation stage. Reported-and-tested-by: syzbot+ff14db38f56329ef68df@syzkaller.appspotmail.com Fixes: 348b59012e5c ("net/9p: Convert net/9p protocol dumps to tracepoints") Signed-off-by: Nikita Zhandarovich Reviewed-by: Christian Schoenebeck Cc: stable@vger.kernel.org Message-ID: <20240408141039.30428-1-n.zhandarovich@fintech.ru> Signed-off-by: Dominique Martinet Signed-off-by: Greg Kroah-Hartman --- net/9p/client.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/9p/client.c +++ b/net/9p/client.c @@ -235,6 +235,8 @@ static int p9_fcall_init(struct p9_clien if (!fc->sdata) return -ENOMEM; fc->capacity = alloc_msize; + fc->id = 0; + fc->tag = P9_NOTAG; return 0; }