From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794064598; b=I3arlbOoUGe4Xp7lVSfx137OrA4e1M4IjzB93OGjtaAwz87wATQnWv9/6jIGyxKKU95Z G2LnqZrNzcs4q85T+ITlbMJgWYz+mWxJQgB/2nNXWN+3CJoLoPWzFFSSh9dthNeWPkyRW jDNjI3m1i+OjlnXi/oDvk4Fb24afmrAjPNjaAs3c9yLa7pUAmhOgF6FOhTH1RqWghqRUv zS7Ng2Ue8sTs1GqQUzK4WaRWDg1gOT7KnsjNMSOxFZHrPLyilDB6tg1k9bwAvnbBeE5Ed RK9EmsXUwRcDu5NakkoPKOArGVGKfumwt9Kq/oJjSrAEiTWL035EtnQWdxJoFdugr7g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794064598; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=zhs9JjDSpmB1rNfi5onROCZMoRpfy9Je8A1WpAzFOgY=; b=la5KxzQp3xQ7BglEAMlX6BrlYNicURMHW2Vp1uBHFHJGOQiB/5xO9WQenEPtc2N/0WHm R6VElN9/U7fxWX5qMlvZonSkbUGikfMgRQXAuFatBMkh1EGaZ0ML4UsLZzKfaDAxJYnT5 GNwdAlqZbHMrI4mbTZAWptxEkTYKBUvW5y5481OWduUOdVu2N+agNqS1lFeUdoThkw03j /eW/E90ACnFynl0k2OEiUVgqFwypn8FWWJnUeOpp4aWb6LsCruzVDrjDQ9eIKNhYFtfS9 gnbeYA5UXhpcc+jf9e53FiTYhmdZvjo2JRMKj51FHo+ZRSp6DM6cTw2e8oJOdMQ946A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=kjJ+rLAF; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 22E71606A9E2; Sat, 7 Nov 2026 15:16:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=kjJ+rLAF Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB23A1F0089F; Sat, 7 Nov 2026 15:16:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794064598; bh=zhs9JjDSpmB1rNfi5onROCZMoRpfy9Je8A1WpAzFOgY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=kjJ+rLAFnP2VjpTt8a2TcBMba89y6LTeJtzed71Z+6mr6N1hVAD19PogSjogCu/MG 3RMNAXRrg8AbfLCSc73I47MCSSVIKQ4cztmwqg8k/hasq2omBshRyIrdQwLpGuXeOc ySRdEq4z6RNZDlbL+OXULfCmcRqL0Gpc0H4DsoiI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jonathan Cameron , Li Ming , "Gregory Price (Meta)" , Alison Schofield , Dave Jiang , Sasha Levin Subject: [PATCH 7.3 0612/1257] cxl/port: Clear cached dport pointers when a dport is removed Date: Sat, 7 Nov 2026 08:48:28 -0500 Message-ID: <20261107134956.210924428@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134939.434104957@linuxfoundation.org> References: <20261107134939.434104957@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dave Jiang [ Upstream commit 019560d23450a320f4060ff235563a5277ea8033 ] Switch decoders cache dport pointers in cxlsd->target[], and nothing clears them when a dport is freed. Readers then dereference freed memory. KASAN caught it under a cxl_test load/unload loop with concurrent sysfs reads (abbreviated). Clear the matching slots from cxl_dport_remove(), walking the port's decoders the way cxl_port_update_decoder_targets() does on the add side. Scan all nr_targets slots, the target[] allocation size, and clear every hit. Fixes: 8330671c57c7 ("cxl: Add helper to delete dport") Cc: stable@vger.kernel.org Assisted-by: LLM Reviewed-by: Jonathan Cameron Reviewed-by: Li Ming Reviewed-by: Gregory Price (Meta) Reviewed-by: Alison Schofield Link: https://patch.msgid.link/20261001154744.1095902-2-dave.jiang@intel.com Signed-off-by: Dave Jiang Signed-off-by: Sasha Levin --- drivers/cxl/core/port.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 625e4aa427db0..6ff3353865e39 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -1089,11 +1089,40 @@ static void cond_cxl_root_unlock(struct cxl_port *port) device_unlock(&port->dev); } +static int clear_decoder_target(struct device *dev, void *data) +{ + struct cxl_dport *dport = data; + struct cxl_switch_decoder *cxlsd; + + if (!is_switch_decoder(dev)) + return 0; + + cxlsd = to_cxl_switch_decoder(dev); + guard(rwsem_write)(&cxl_rwsem.region); + + /* + * A dport can occupy more than one position of an interleave, so + * scan the whole target list rather than stopping at the first hit. + */ + for (int i = 0; i < cxlsd->nr_targets; i++) { + if (cxlsd->target[i] != dport) + continue; + cxlsd->target[i] = NULL; + dev_dbg(dev, "dport%d removed from target list, index %d\n", + dport->port_id, i); + } + + return 0; +} + static void cxl_dport_remove(void *data) { struct cxl_dport *dport = data; struct cxl_port *port = dport->port; + /* counterpart of cxl_port_update_decoder_targets() */ + device_for_each_child(&port->dev, dport, clear_decoder_target); + port->nr_dports--; xa_erase(&port->dports, (unsigned long) dport->dport_dev); put_device(dport->dport_dev); -- 2.53.0