From patchwork Mon Jun 24 08:07:47 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniil Dulov X-Patchwork-Id: 13709139 X-Patchwork-Delegate: bpf@iogearbox.net Received: from mail-out.aladdin-rd.ru (mail-out.aladdin-rd.ru [91.199.251.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 94C3447F6C; Mon, 24 Jun 2024 08:08:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.199.251.16 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719216518; cv=none; b=WgDbHyOTYBu62lV0FBwENghT9dA4p56zL184I5wlJSiQiMdMGaY62Sb7LBqixNF5KpOX3Ox50OvnAuPcDRgiDPObq0SNSGbC79qwZKen8Fgfy5DwAfNVQayvxtc0kwRPhyucFhmE7k2FCwsEGSRO0PRXkarSj2TCh2amAnK6RbQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719216518; c=relaxed/simple; bh=1EfVWLN8EujHeW9ugE6PQVP6G/uH1aYrSaJvrCJ+/xA=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=S6yYMyNuHseliQeJG95Q0HXBEJ+3D7sDtfv6lhkj0HB6k1+CEeSN49p9NivdLmqxqKZRJlQ5IQ5OnFomyuF87ZJmf6LFA/augfkhkcRQcyB7eaCrjn9CiONA4dTw/4MJtfQQvL7vkZaGhfd9LZyRgAB8yfR0pM1qla0vG6BTs5c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=aladdin.ru; spf=pass smtp.mailfrom=aladdin.ru; arc=none smtp.client-ip=91.199.251.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=aladdin.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=aladdin.ru From: Daniil Dulov To: Alexei Starovoitov CC: Daniil Dulov , Daniel Borkmann , "David S. Miller" , Jakub Kicinski , Jesper Dangaard Brouer , John Fastabend , Eric Dumazet , Paolo Abeni , , , , Subject: [PATCH v2] xdp: remove WARN() from __xdp_reg_mem_model() Date: Mon, 24 Jun 2024 11:07:47 +0300 Message-ID: <20240624080747.36858-1-d.dulov@aladdin.ru> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: EXCH-2016-01.aladdin.ru (192.168.1.101) To EXCH-2016-01.aladdin.ru (192.168.1.101) X-Patchwork-Delegate: kuba@kernel.org Syzkaller reports a warning in __xdp_reg_mem_model(). The warning occurs only if __mem_id_init_hash_table() returns an error. It returns the error in two cases: 1. memory allocation fails; 2. rhashtable_init() fails when some fields of rhashtable_params struct are not initialized properly. The second case cannot happen since there is a static const rhashtable_params struct with valid fields. So, warning is only triggered when there is a problem with memory allocation. Thus, there is no sense in using WARN() to handle this error and it can be safely removed. WARNING: CPU: 0 PID: 5065 at net/core/xdp.c:299 __xdp_reg_mem_model+0x2d9/0x650 net/core/xdp.c:299 CPU: 0 PID: 5065 Comm: syz-executor883 Not tainted 6.8.0-syzkaller-05271-gf99c5f563c17 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:__xdp_reg_mem_model+0x2d9/0x650 net/core/xdp.c:299 Call Trace: xdp_reg_mem_model+0x22/0x40 net/core/xdp.c:344 xdp_test_run_setup net/bpf/test_run.c:188 [inline] bpf_test_run_xdp_live+0x365/0x1e90 net/bpf/test_run.c:377 bpf_prog_test_run_xdp+0x813/0x11b0 net/bpf/test_run.c:1267 bpf_prog_test_run+0x33a/0x3b0 kernel/bpf/syscall.c:4240 __sys_bpf+0x48d/0x810 kernel/bpf/syscall.c:5649 __do_sys_bpf kernel/bpf/syscall.c:5738 [inline] __se_sys_bpf kernel/bpf/syscall.c:5736 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: 8d5d88527587 ("xdp: rhashtable with allocator ID to pointer mapping") Signed-off-by: Daniil Dulov Acked-by: Jesper Dangaard Brouer --- v2: Removed unnecessary brackets as Jakub Kicinski suggested, also added Acked-by Jesper Dangaard Brouer Link: https://lore.kernel.org/all/20240617162708.492159-1-d.dulov@aladdin.ru/ net/core/xdp.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/net/core/xdp.c b/net/core/xdp.c index 41693154e426..022c12059cf2 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -295,10 +295,8 @@ static struct xdp_mem_allocator *__xdp_reg_mem_model(struct xdp_mem_info *mem, mutex_lock(&mem_id_lock); ret = __mem_id_init_hash_table(); mutex_unlock(&mem_id_lock); - if (ret < 0) { - WARN_ON(1); + if (ret < 0) return ERR_PTR(ret); - } } xdp_alloc = kzalloc(sizeof(*xdp_alloc), gfp);