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 62CB43264F4; Sat, 12 Sep 2026 13:50:02 +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=1789221003; cv=none; b=ZRDH56XVEz/HdO58+zvivQT1zIS+W2mjoLi5cmuNBIWFK08Gw0P05Q37E0CDmeWDVTsXJ3gFPPL+qkOiSCuwmQMYINy94hG7Eaj0TzJMVGxx/QbMY/RSSqHrz7UL7wePsSerP1CaYNRs8gBWxAA1c3uIQV6EpaCTYFPJFhVFYV0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789221003; c=relaxed/simple; bh=8H+NZfDyLQ62JBa+rOezKp83xasUJ/abrM7LZ5z5ApI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SkKGK01O+TkamsClXwPFe3H9UDiw4rzucMbUcnaWUPUzpSTig6uBR/KQx1Xu+MucDPzPgAlyOeoPskEPc8Bo4DlkIYJksM9iZunmVpqGEFimaR8s/HbY1S5Rb1SL5xCa386b+yGh9he/5rotfXMrr9i1mj2oWTU3wX8cuSMvMak= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sxQvs+Jz; 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="sxQvs+Jz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 992AB1F000FF; Sat, 12 Sep 2026 13:50:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789221002; bh=tk/9miMD3H6uiu0wXQjoCi8wqhP/fhk7l5kwoX56XQ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=sxQvs+Jzalg2ajXCXZvJIj+dXlg2IBigJ7t3M9K7kTvyYkf5gv9HtV5cfJeoRCevm RSxLHRCUSZcdT8Trrb4cMnb38MNbEIXH5f/6Alo7S3KOLvEg0+jBvMPv6UBIdcc3m0 JR5iDS1h0KooConxbHfWlPYQ/l/fxTqRf0vp6YnA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kaixuan Li , Maoyi Xie , Frank Li , Alexandre Belloni Subject: [PATCH 6.6 0292/1424] i3c: master: svc: bound IBI payload to the requested max_payload_len Date: Sat, 12 Sep 2026 08:45:24 +0200 Message-ID: <20260912065613.823901113@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.279695368@linuxfoundation.org> References: <20260912065607.279695368@linuxfoundation.org> User-Agent: quilt/0.69 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maoyi Xie commit e2bda39d7f9f285ec803e200b5c1f17143d0b483 upstream. svc_i3c_master_handle_ibi() reads the IBI payload from the RX FIFO into the IBI slot. The loop is bounded by the hardware FIFO size (SVC_I3C_FIFO_SIZE), not by the slot size. slot->data points into the IBI pool, which i3c_generic_ibi_alloc_pool() sizes at max_payload_len per slot. svc_i3c_master_request_ibi() only rejects a max_payload_len larger than SVC_I3C_FIFO_SIZE, so a driver can request a smaller one. mctp-i3c requests 1. Each readsb() then copies the controller RXCOUNT bytes (up to 31) with no check against the slot size. A device that sends more bytes than the slot holds writes past slot->data, an out-of-bounds write into the IBI pool. Bound the loop by dev->ibi->max_payload_len and clamp each read to the space left in the slot, the same way dw-i3c does. A device can still send more than the requested payload. Flush the leftover bytes from the RX FIFO so they do not leak into the next transfer. Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver") Cc: stable@vger.kernel.org Co-developed-by: Kaixuan Li Signed-off-by: Kaixuan Li Signed-off-by: Maoyi Xie Reviewed-by: Frank Li Link: https://patch.msgid.link/178227747353.2931373.15868718612134648277@maoyixie.com Signed-off-by: Alexandre Belloni Signed-off-by: Greg Kroah-Hartman --- drivers/i3c/master/svc-i3c-master.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/i3c/master/svc-i3c-master.c +++ b/drivers/i3c/master/svc-i3c-master.c @@ -380,14 +380,22 @@ static int svc_i3c_master_handle_ibi(str buf = slot->data; while (SVC_I3C_MSTATUS_RXPEND(readl(master->regs + SVC_I3C_MSTATUS)) && - slot->len < SVC_I3C_FIFO_SIZE) { + slot->len < dev->ibi->max_payload_len) { mdatactrl = readl(master->regs + SVC_I3C_MDATACTRL); count = SVC_I3C_MDATACTRL_RXCOUNT(mdatactrl); + count = min(count, dev->ibi->max_payload_len - slot->len); readsb(master->regs + SVC_I3C_MRDATAB, buf, count); slot->len += count; buf += count; } + /* + * The device may have sent more than the requested payload. Drop the + * extra bytes so they do not leak into the next transfer. + */ + if (SVC_I3C_MSTATUS_RXPEND(readl(master->regs + SVC_I3C_MSTATUS))) + writel(SVC_I3C_MDATACTRL_FLUSHRB, master->regs + SVC_I3C_MDATACTRL); + master->ibi.tbq_slot = slot; return 0;