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 7881F37F306; Fri, 4 Sep 2026 06:02:26 +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=1788501747; cv=none; b=idfHtCt/B22oCZBARl/LPrOWf1Pw/jmJwRolV+2gLi35qRE82x2mrsDy3UUFapNdiaYUQdTFVuXKCbiMZGzYl4jaqSRIYXUOFLvc3tAB/yhJqSvMBH8PIKXm+C9wFevhuIz0LJhjxjYpBFCZYYdvo2ehbVKc+B8WPr9hIqCRTZ8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788501747; c=relaxed/simple; bh=gIYzswMsh9V/17BB0UawxIsIYwIdrKH/fMpIZzLHMpw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GuaaqYvrb+iHoA5CCZT8go4Qva9vNfWALJu/T768q5SMtw+ShlPa3S96yDDkVeAd9J9EpQ81Xy2KRgNxHNGatitajuFJwZs2zZXdgWlWlWbSpk0PkinpkyNpDGUPO8YqLc+WhZSTYE8jl1pCOdEgYzl/N87SxKkwy/9SVC9uSVw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=aAQx3jcl; 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="aAQx3jcl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3B471F00A3D; Fri, 4 Sep 2026 06:02:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788501746; bh=d4exBFyRA1HNST+IbbKz3yv10bw8St9r8upxBPkUruo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=aAQx3jclOnMkpQIf7uCf58wLQQekLEa6iiUyGxvYaivzhD8bZ3blmyje4j4180aDZ EP/Xu2mZEc+ISBxCIR45o8Bu1HBvk2I8tzfzNPL1B+Ukr6J6oCubtTsoHFIuqTztqK d53cy5kGHkEEc6CUW6fkVuG1vDnvzt/beWmGYFDA= 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 6.18 517/552] i3c: master: svc: bound IBI payload to the requested max_payload_len Date: Fri, 4 Sep 2026 07:01:14 +0200 Message-ID: <20260904045802.350976678@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045747.813364717@linuxfoundation.org> References: <20260904045747.813364717@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 6.18-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 @@ -418,14 +418,22 @@ 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;