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 31A7369954; Wed, 21 Feb 2024 13:11:41 +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=1708521101; cv=none; b=hGxR6BtISHAhmnB/WkmU/e0LdHOtFMqA1BC2qk5aN2JZn3PUQcqKy6Eno0TUMheExpETAdMh/Mfr0YHSe3OT7j+sESitv7AjsDPbDcrfvOYwpnYEj2kU/ErhCNoDgrXbUIxmGXikiPa5Nyg9QPwQ5rIVpzQKUU933Frp35lk77Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708521101; c=relaxed/simple; bh=EHiwvRMFHEdt7x1LHOjHyjMeRc57HVEd7STQJgclRTQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=l7XZSq3nBZpKKXHAK6heTvKcU2pQFqZRyrioirUHHmrhgLn+25KeQSDJCztMxe2L539qDerNsgN86IHjFU6PCcR/XYwq//7iXMaG8zcTARccMoVptR9ebqdoeLJv5N3oOL76phij6EKMZWUkaXK+cKx1CY7cBehnCu1Mnl0m7Zw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=jPbmfEra; 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="jPbmfEra" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9C3E9C433F1; Wed, 21 Feb 2024 13:11:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1708521101; bh=EHiwvRMFHEdt7x1LHOjHyjMeRc57HVEd7STQJgclRTQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jPbmfErag8cufGnDNfDf5xwc4v/cFsvrTgUPnEoNUsB7rBm/nYi1k24vMah/C8JhB GS2EhMQZmub4iTQXhI+ma/cwdQ5fp5mc6nH2T16oUrIDu9FLmH1nKzPJaX9+hO+dGg GuLYDmzltOYNqTnBRDUTpbIGuyd5kaNJYLS22JyI= 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 4.19 024/202] net/smc: fix illegal rmb_desc access in SMC-D connection dump Date: Wed, 21 Feb 2024 14:05:25 +0100 Message-ID: <20240221125932.554416591@linuxfoundation.org> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240221125931.742034354@linuxfoundation.org> References: <20240221125931.742034354@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-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 6c4a7a5938b7..3ab14678afff 100644 --- a/net/smc/smc_diag.c +++ b/net/smc/smc_diag.c @@ -167,7 +167,7 @@ static int __smc_diag_dump(struct sock *sk, struct sk_buff *skb, } if (smc->conn.lgr && 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