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 61D4A15A49E; Mon, 29 Jan 2024 17:11:37 +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=1706548297; cv=none; b=IgEo02B/vyxZoAE9UjHfU2Jt4OyS5TVvspxYl7BvSNFVAQaCeoE+s9xqh4a7QTetUERNF37VThluDhB6QhiYRTwPmaKydyD0JDxSQ/2KYOzq6aWFVXXhODa7+qsHQABt8XAbqwHh3QK6aNYABbQz+b4agJJBhKP2YSbdXZKuRqU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706548297; c=relaxed/simple; bh=keEZ6RkiIvnUS2isTSZ5L0EkfEbVIzO2MF/XvsNqVL4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=L8RlmiUnJaNNEgXdloYpmFreKu+xKuMDTgamD3VX3E9NxkzdVF3xFkhDeOeVNViGKMn9l3+AphsSDX+ZkBewguCVA7xyMDFGcCffLCqVVasX+eDJoSKIuzCxvC0n5X4bdtazLeGP6pkTXiDi5oHAAUTcpLIfCqWFMgAxqAJ23zI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=EEIYzhhu; 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="EEIYzhhu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2922EC433C7; Mon, 29 Jan 2024 17:11:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1706548297; bh=keEZ6RkiIvnUS2isTSZ5L0EkfEbVIzO2MF/XvsNqVL4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EEIYzhhuTd+RcPK1s5/i/jzOn/aQljyu1Fcw88CIeYMGJnWrJHuQg2hgg3q6UOuBM VfBGGfQ1Tvz5XOdRJc6TC1CoObxS7SgvIs3atdNv5WWKxFRnl3eLJYaXwCRGR67Fzy 4RhDzCGDHRrMND5blRRyZTnHB4EPrfPM5btWxFbY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Wen Gu , Dust Li , Wenjia Zhang , "David S. Miller" , Sasha Levin Subject: [PATCH 6.1 077/185] net/smc: fix illegal rmb_desc access in SMC-D connection dump Date: Mon, 29 Jan 2024 09:04:37 -0800 Message-ID: <20240129170001.078129579@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240129165958.589924174@linuxfoundation.org> References: <20240129165958.589924174@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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wen Gu [ Upstream commit dbc153fd3c142909e564bb256da087e13fbf239c ] A crash was found when dumping SMC-D connections. It can be reproduced by following steps: - run nginx/wrk test: smc_run nginx smc_run wrk -t 16 -c 1000 -d -H 'Connection: Close' - continuously dump SMC-D connections in parallel: watch -n 1 'smcss -D' BUG: kernel NULL pointer dereference, address: 0000000000000030 CPU: 2 PID: 7204 Comm: smcss Kdump: loaded Tainted: G E 6.7.0+ #55 RIP: 0010:__smc_diag_dump.constprop.0+0x5e5/0x620 [smc_diag] Call Trace: ? __die+0x24/0x70 ? page_fault_oops+0x66/0x150 ? exc_page_fault+0x69/0x140 ? asm_exc_page_fault+0x26/0x30 ? __smc_diag_dump.constprop.0+0x5e5/0x620 [smc_diag] ? __kmalloc_node_track_caller+0x35d/0x430 ? __alloc_skb+0x77/0x170 smc_diag_dump_proto+0xd0/0xf0 [smc_diag] smc_diag_dump+0x26/0x60 [smc_diag] netlink_dump+0x19f/0x320 __netlink_dump_start+0x1dc/0x300 smc_diag_handler_dump+0x6a/0x80 [smc_diag] ? __pfx_smc_diag_dump+0x10/0x10 [smc_diag] sock_diag_rcv_msg+0x121/0x140 ? __pfx_sock_diag_rcv_msg+0x10/0x10 netlink_rcv_skb+0x5a/0x110 sock_diag_rcv+0x28/0x40 netlink_unicast+0x22a/0x330 netlink_sendmsg+0x1f8/0x420 __sock_sendmsg+0xb0/0xc0 ____sys_sendmsg+0x24e/0x300 ? copy_msghdr_from_user+0x62/0x80 ___sys_sendmsg+0x7c/0xd0 ? __do_fault+0x34/0x160 ? do_read_fault+0x5f/0x100 ? do_fault+0xb0/0x110 ? __handle_mm_fault+0x2b0/0x6c0 __sys_sendmsg+0x4d/0x80 do_syscall_64+0x69/0x180 entry_SYSCALL_64_after_hwframe+0x6e/0x76 It is possible that the connection is in process of being established when we dump it. Assumed that the connection has been registered in a link group by smc_conn_create() but the rmb_desc has not yet been initialized by smc_buf_create(), thus causing the illegal access to conn->rmb_desc. So fix it by checking before dump. Fixes: 4b1b7d3b30a6 ("net/smc: add SMC-D diag support") Signed-off-by: Wen Gu Reviewed-by: Dust Li Reviewed-by: Wenjia Zhang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/smc/smc_diag.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/smc/smc_diag.c b/net/smc/smc_diag.c index 801044e7d194..7a907186a33a 100644 --- a/net/smc/smc_diag.c +++ b/net/smc/smc_diag.c @@ -163,7 +163,7 @@ static int __smc_diag_dump(struct sock *sk, struct sk_buff *skb, } if (smc_conn_lgr_valid(&smc->conn) && smc->conn.lgr->is_smcd && (req->diag_ext & (1 << (SMC_DIAG_DMBINFO - 1))) && - !list_empty(&smc->conn.lgr->list)) { + !list_empty(&smc->conn.lgr->list) && smc->conn.rmb_desc) { struct smc_connection *conn = &smc->conn; struct smcd_diag_dmbinfo dinfo; -- 2.43.0