From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 842A2C76191 for ; Mon, 15 Jul 2019 14:17:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5CD5F20651 for ; Mon, 15 Jul 2019 14:17:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563200263; bh=Ew34IS4c/YSyOPNEahM7m8KTTx0XZaWp+16rB2LbThU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=J8CPgcZjjkyVbV7mcYPe7AM8HdbMutlpznQyqh8SnLqoKTuoljq77+FLUvlN5QwrP Qn2qsPvfBRJaCcQYt/Qgh/0liNwloMTO735mYgBduEWZ2ThIFCkkm4c9gw/vX1jUaa UojDN7UjhVFrlgmrWWAXr7un2KosrxodYbJB8m4g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389585AbfGOORl (ORCPT ); Mon, 15 Jul 2019 10:17:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:37086 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389291AbfGOORj (ORCPT ); Mon, 15 Jul 2019 10:17:39 -0400 Received: from sasha-vm.mshome.net (unknown [73.61.17.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4BA38206B8; Mon, 15 Jul 2019 14:17:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563200258; bh=Ew34IS4c/YSyOPNEahM7m8KTTx0XZaWp+16rB2LbThU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rBOzOacrg5n7nmwKCCAMi4rBmEoCUk5DNz9ot0YfYDuKzeqvZ9UgO3gbBPw6wmXDj TbJDYR0s4hne6429oq/muTtxOmoWTzOMkdv9GtkTov/ZwsNSvomcjtdn4oTdykgECX QkwKfXKgoiP2jBM/FjWI3a5+TDP7aTEHI+Rvq/8w= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Taehee Yoo , "David S . Miller" , Sasha Levin , osmocom-net-gprs@lists.osmocom.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.1 215/219] gtp: fix Illegal context switch in RCU read-side critical section. Date: Mon, 15 Jul 2019 10:03:36 -0400 Message-Id: <20190715140341.6443-215-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190715140341.6443-1-sashal@kernel.org> References: <20190715140341.6443-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Taehee Yoo [ Upstream commit 3f167e1921865b379a9becf03828e7202c7b4917 ] ipv4_pdp_add() is called in RCU read-side critical section. So GFP_KERNEL should not be used in the function. This patch make ipv4_pdp_add() to use GFP_ATOMIC instead of GFP_KERNEL. Test commands: gtp-link add gtp1 & gtp-tunnel add gtp1 v1 100 200 1.1.1.1 2.2.2.2 Splat looks like: [ 130.618881] ============================= [ 130.626382] WARNING: suspicious RCU usage [ 130.626994] 5.2.0-rc6+ #50 Not tainted [ 130.627622] ----------------------------- [ 130.628223] ./include/linux/rcupdate.h:266 Illegal context switch in RCU read-side critical section! [ 130.629684] [ 130.629684] other info that might help us debug this: [ 130.629684] [ 130.631022] [ 130.631022] rcu_scheduler_active = 2, debug_locks = 1 [ 130.632136] 4 locks held by gtp-tunnel/1025: [ 130.632925] #0: 000000002b93c8b7 (cb_lock){++++}, at: genl_rcv+0x15/0x40 [ 130.634159] #1: 00000000f17bc999 (genl_mutex){+.+.}, at: genl_rcv_msg+0xfb/0x130 [ 130.635487] #2: 00000000c644ed8e (rtnl_mutex){+.+.}, at: gtp_genl_new_pdp+0x18c/0x1150 [gtp] [ 130.636936] #3: 0000000007a1cde7 (rcu_read_lock){....}, at: gtp_genl_new_pdp+0x187/0x1150 [gtp] [ 130.638348] [ 130.638348] stack backtrace: [ 130.639062] CPU: 1 PID: 1025 Comm: gtp-tunnel Not tainted 5.2.0-rc6+ #50 [ 130.641318] Call Trace: [ 130.641707] dump_stack+0x7c/0xbb [ 130.642252] ___might_sleep+0x2c0/0x3b0 [ 130.642862] kmem_cache_alloc_trace+0x1cd/0x2b0 [ 130.643591] gtp_genl_new_pdp+0x6c5/0x1150 [gtp] [ 130.644371] genl_family_rcv_msg+0x63a/0x1030 [ 130.645074] ? mutex_lock_io_nested+0x1090/0x1090 [ 130.645845] ? genl_unregister_family+0x630/0x630 [ 130.646592] ? debug_show_all_locks+0x2d0/0x2d0 [ 130.647293] ? check_flags.part.40+0x440/0x440 [ 130.648099] genl_rcv_msg+0xa3/0x130 [ ... ] Fixes: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Signed-off-by: Taehee Yoo Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/gtp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index f45a806b6c06..6f1ad7ccaea6 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -958,7 +958,7 @@ static int ipv4_pdp_add(struct gtp_dev *gtp, struct sock *sk, } - pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL); + pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC); if (pctx == NULL) return -ENOMEM; -- 2.20.1