From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 66F814B0492; Mon, 17 Aug 2026 13:39:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786973998; cv=none; b=O6P2McWOwu2ZF7Z9txZEIbh++41G/C8UvcZaNs5cg2hEywu3buBe4IQPn+sdRQ+GpM28OTkYcAK6JNCZsKmJYNiGtDzOta2CO0ThJdcgee//hflYDI2fgb8SBHbOthryPPhrsBi315fANrjWMq5UW4AE/xxT4GDESqIW0lFgN7c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786973998; c=relaxed/simple; bh=jxxEmfR/qEv6MOqA3UKkXozNOCoGtorDbaylQKBS13o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rUnmFuSBnUJhultZrUpGjLJYkgQwZXNaORBJc2UdRV6ne2Rrzp0b/ZfWLTkiidU/S3r2RE4pRcxkCzuW6TI5fRQFelj22xI9FdMXGJwOMEo+zA6O5mdF3SHSlQyXFR0JGe/j5/Zi2m4b2gZcB7al+dkZHJPNs+08Qxf7QcXqY4g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=oQNtTeT4; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="oQNtTeT4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 862991F000E9; Mon, 17 Aug 2026 13:39:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786973997; bh=R5fM0eYvp6TrtGPTI+S5qBfPuRIHsB2vsvDGRhPdEhw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=oQNtTeT4VQUOlFm2OCwUuwpA/gsLeXpNUGbuWNd8wzfkG+c2YGzzahBYcangEqdqb 0pGhmEt6aYMq6RG4sG7WovOgJVZ2W45mNx5Rsb1dxSk0ter57FepTh3fdKpDBVOVmJ icTTIsqkVF3UuYUzGRA7pSRunTkyf99d9YSQL7D4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mahanta Jambigi , Hidayath Khan , Sidraya Jayagond , Dust Li , Jakub Kicinski , Sasha Levin Subject: [PATCH 7.1 054/271] net/smc: fix qentry overwrite for CONFIRM_LINK and ADD_LINK_CONT in smc_llc_event_handler() Date: Mon, 17 Aug 2026 15:29:39 +0200 Message-ID: <20260817132538.965415828@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132536.752504388@linuxfoundation.org> References: <20260817132536.752504388@linuxfoundation.org> User-Agent: quilt/0.69 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 7.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mahanta Jambigi [ Upstream commit 976245094925bab9bc39366b2e9ab44ffcde61d0 ] The SMC_LLC_CONFIRM_LINK / SMC_LLC_ADD_LINK_CONT branch in smc_llc_event_handler() stores an incoming qentry into the local LLC flow without first checking whether a qentry is already pending. If a malicious or buggy peer sends a second CONFIRM_LINK or ADD_LINK_CONT request while a flow is active and flow->qentry is already set, smc_llc_flow_qentry_set() overwrites the pointer without freeing the previous allocation, leaking one kmalloc-96 object per spurious message. The sibling SMC_LLC_DELETE_LINK branch already has the correct !flow->qentry guard. Apply the same guard to the CONFIRM_LINK/ADD_LINK_CONT branch so that a duplicate message when qentry is already occupied falls through to break and is freed by the kfree(qentry) at the out: label, rather than silently leaking the existing allocation. The response direction (smc_llc_rx_response()) is unaffected: it already guards with flow->qentry at the equivalent site and drops duplicate responses correctly. Fixes: 0fb0b02bd6fd ("net/smc: adapt SMC client code to use the LLC flow") Signed-off-by: Mahanta Jambigi Reviewed-by: Hidayath Khan Reviewed-by: Sidraya Jayagond Reviewed-by: Dust Li Link: https://patch.msgid.link/20260729130153.970800-1-mjambigi@linux.ibm.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/smc/smc_llc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c index 954b2ff1815c2..aa6d83af55eda 100644 --- a/net/smc/smc_llc.c +++ b/net/smc/smc_llc.c @@ -1927,7 +1927,8 @@ static void smc_llc_event_handler(struct smc_llc_qentry *qentry) return; case SMC_LLC_CONFIRM_LINK: case SMC_LLC_ADD_LINK_CONT: - if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) { + if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE && + !lgr->llc_flow_lcl.qentry) { /* a flow is waiting for this message */ smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry); wake_up(&lgr->llc_msg_waiter); -- 2.53.0