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 489924B5AB; Mon, 8 Jan 2024 15:13:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="v+7XqTxr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD3B0C433CD; Mon, 8 Jan 2024 15:13:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1704726810; bh=CvqY9KojVgMmCkV69pmoARO0frIAL6LK103Ellmpr30=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=v+7XqTxrhz9SQ/o29NM6eiOMVee2PHyvFVmcYS8u8mXg1HLHrLJDmfkhnYqIHk7Gy Bg469ouTVaTIU1VcFaK2ElK6Bp93bHZQkk11WU3VvREstegxca3KObv4G3ojyWPTb8 jrHVrDnGRrcrnRTjYOS6FavGJc666hg2z4fU5XSc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, henaumars , Wen Gu , Tony Lu , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 056/124] net/smc: fix invalid link access in dumping SMC-R connections Date: Mon, 8 Jan 2024 16:08:02 +0100 Message-ID: <20240108150605.536891676@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240108150602.976232871@linuxfoundation.org> References: <20240108150602.976232871@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wen Gu [ Upstream commit 9dbe086c69b8902c85cece394760ac212e9e4ccc ] A crash was found when dumping SMC-R connections. It can be reproduced by following steps: - environment: two RNICs on both sides. - run SMC-R between two sides, now a SMC_LGR_SYMMETRIC type link group will be created. - set the first RNIC down on either side and link group will turn to SMC_LGR_ASYMMETRIC_LOCAL then. - run 'smcss -R' and the crash will be triggered. BUG: kernel NULL pointer dereference, address: 0000000000000010 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 8000000101fdd067 P4D 8000000101fdd067 PUD 10ce46067 PMD 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 3 PID: 1810 Comm: smcss Kdump: loaded Tainted: G W E 6.7.0-rc6+ #51 RIP: 0010:__smc_diag_dump.constprop.0+0x36e/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+0x36e/0x620 [smc_diag] 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+0x240/0x4a0 __sock_sendmsg+0xb0/0xc0 ____sys_sendmsg+0x24e/0x300 ? copy_msghdr_from_user+0x62/0x80 ___sys_sendmsg+0x7c/0xd0 ? __do_fault+0x34/0x1a0 ? do_read_fault+0x5f/0x100 ? do_fault+0xb0/0x110 __sys_sendmsg+0x4d/0x80 do_syscall_64+0x45/0xf0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 When the first RNIC is set down, the lgr->lnk[0] will be cleared and an asymmetric link will be allocated in lgr->link[SMC_LINKS_PER_LGR_MAX - 1] by smc_llc_alloc_alt_link(). Then when we try to dump SMC-R connections in __smc_diag_dump(), the invalid lgr->lnk[0] will be accessed, resulting in this issue. So fix it by accessing the right link. Fixes: f16a7dd5cf27 ("smc: netlink interface for SMC sockets") Reported-by: henaumars Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=7616 Signed-off-by: Wen Gu Reviewed-by: Tony Lu Link: https://lore.kernel.org/r/1703662835-53416-1-git-send-email-guwen@linux.alibaba.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/smc/smc_diag.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/smc/smc_diag.c b/net/smc/smc_diag.c index 7ff2152971a5b..2c464d76b06ce 100644 --- a/net/smc/smc_diag.c +++ b/net/smc/smc_diag.c @@ -153,8 +153,7 @@ static int __smc_diag_dump(struct sock *sk, struct sk_buff *skb, .lnk[0].link_id = link->link_id, }; - memcpy(linfo.lnk[0].ibname, - smc->conn.lgr->lnk[0].smcibdev->ibdev->name, + memcpy(linfo.lnk[0].ibname, link->smcibdev->ibdev->name, sizeof(link->smcibdev->ibdev->name)); smc_gid_be16_convert(linfo.lnk[0].gid, link->gid); smc_gid_be16_convert(linfo.lnk[0].peer_gid, link->peer_gid); -- 2.43.0