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 F09196FB5 for ; Sun, 17 Sep 2023 20:41:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6319BC433C8; Sun, 17 Sep 2023 20:41:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694983277; bh=NGuAonsCpXSHsbjTnEtCymeyRXLM7spNiP9pcGzbT+Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NOeNiRyAAPQXjtjW6ae+4NObHbZfVNKOIxykzIGRhD9oJkMLt3Q44KVAMX2ZBHnlE ybIxryQUjoFuWrYLWwteFfo8mgPXlZjJ80jboaNkWJnmxI9oYE556IStYu8+88DJpM O4GusoDNiOQsJ1pBZOS7yXFQsRlUvbArZs+J3n0Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Guangguan Wang , "David S. Miller" , Sasha Levin Subject: [PATCH 5.15 495/511] net/smc: use smc_lgr_list.lock to protect smc_lgr_list.list iterate in smcr_port_add Date: Sun, 17 Sep 2023 21:15:22 +0200 Message-ID: <20230917191125.680711319@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230917191113.831992765@linuxfoundation.org> References: <20230917191113.831992765@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guangguan Wang [ Upstream commit f5146e3ef0a9eea405874b36178c19a4863b8989 ] While doing smcr_port_add, there maybe linkgroup add into or delete from smc_lgr_list.list at the same time, which may result kernel crash. So, use smc_lgr_list.lock to protect smc_lgr_list.list iterate in smcr_port_add. The crash calltrace show below: BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 0 PID: 559726 Comm: kworker/0:92 Kdump: loaded Tainted: G Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 449e491 04/01/2014 Workqueue: events smc_ib_port_event_work [smc] RIP: 0010:smcr_port_add+0xa6/0xf0 [smc] RSP: 0000:ffffa5a2c8f67de0 EFLAGS: 00010297 RAX: 0000000000000001 RBX: ffff9935e0650000 RCX: 0000000000000000 RDX: 0000000000000010 RSI: ffff9935e0654290 RDI: ffff9935c8560000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff9934c0401918 R10: 0000000000000000 R11: ffffffffb4a5c278 R12: ffff99364029aae4 R13: ffff99364029aa00 R14: 00000000ffffffed R15: ffff99364029ab08 FS: 0000000000000000(0000) GS:ffff994380600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000f06a10003 CR4: 0000000002770ef0 PKRU: 55555554 Call Trace: smc_ib_port_event_work+0x18f/0x380 [smc] process_one_work+0x19b/0x340 worker_thread+0x30/0x370 ? process_one_work+0x340/0x340 kthread+0x114/0x130 ? __kthread_cancel_work+0x50/0x50 ret_from_fork+0x1f/0x30 Fixes: 1f90a05d9ff9 ("net/smc: add smcr_port_add() and smcr_link_up() processing") Signed-off-by: Guangguan Wang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/smc/smc_core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index f08fcc50fad3c..b84896acd4732 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -1486,6 +1486,7 @@ void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport) { struct smc_link_group *lgr, *n; + spin_lock_bh(&smc_lgr_list.lock); list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) { struct smc_link *link; @@ -1500,6 +1501,7 @@ void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport) if (link) smc_llc_add_link_local(link); } + spin_unlock_bh(&smc_lgr_list.lock); } /* link is down - switch connections to alternate link, -- 2.40.1