From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 65718D58CCA for ; Tue, 24 Mar 2026 09:12:25 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D922110E63E; Tue, 24 Mar 2026 09:12:23 +0000 (UTC) Received: from cstnet.cn (smtp25.cstnet.cn [159.226.251.25]) by gabe.freedesktop.org (Postfix) with ESMTPS id D4FC210E27B for ; Tue, 24 Mar 2026 01:45:03 +0000 (UTC) Received: from localhost.localdomain (unknown [111.196.245.197]) by APP-05 (Coremail) with SMTP id zQCowAA3zRCb7MFpzq5JCw--.35583S2; Tue, 24 Mar 2026 09:44:59 +0800 (CST) From: Pengpeng Hou To: srini@kernel.org, amahesh@qti.qualcomm.com, arnd@arndb.de, gregkh@linuxfoundation.org Cc: linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, pengpeng@iscas.ac.cn Subject: [PATCH] misc: fastrpc: keep copied arguments inside the invoke buffer Date: Tue, 24 Mar 2026 09:44:59 +0800 Message-ID: <20260324014459.93364-1-pengpeng@iscas.ac.cn> X-Mailer: git-send-email 2.50.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: zQCowAA3zRCb7MFpzq5JCw--.35583S2 X-Coremail-Antispam: 1UD129KBjvJXoW7Kw18Ar4xWFy3CFW5WrW3ZFb_yoW8uw13pF 45Ka1ruF45Xw47GF1vyFnrWryfJws3J34UGrZ3G34S9w1aqFy0gFyqkFyj9a40krZ2vry0 krs8taya9a17JaUanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkC14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUXVWUAwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26ryj6F1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UM28EF7xvwVC2z280aVAFwI0_Cr1j6rxdM28EF7xvwVC2z280aVCY1x0267AKxVWxJr 0_GcWle2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E 2Ix0cI8IcVAFwI0_Jrv_JF1lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lc7CjxVAaw2AFwI0_ JF0_Jw1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67 AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIY rxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14 v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8 JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfUecTmDU UUU X-Originating-IP: [111.196.245.197] X-CM-SenderInfo: pshqw1xhqjqxpvfd2hldfou0/ X-Mailman-Approved-At: Tue, 24 Mar 2026 09:12:22 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" fastrpc_get_args() derives rpra[i].buf.pv from the overlap offset that was computed from user-controlled argument pointers and lengths. The resulting destination pointer is then used for copy_from_user() without first checking that it still falls inside the allocated invoke buffer. Validate the overlap-derived destination range before storing it in rpra[i].buf.pv and before copying inline arguments into the invoke buffer. --- drivers/misc/fastrpc.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c index 47356a5d5804..d7f53300b899 100644 --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -993,6 +993,7 @@ static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx) u64 len, rlen, pkt_size; u64 pg_start, pg_end; uintptr_t args; + uintptr_t buf_start, buf_end; int metalen; inbufs = REMOTE_SCALARS_INBUFS(ctx->sc); @@ -1016,6 +1017,8 @@ static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx) rpra = ctx->buf->virt; list = fastrpc_invoke_buf_start(rpra, ctx->nscalars); pages = fastrpc_phy_page_start(list, ctx->nscalars); + buf_start = (uintptr_t)ctx->buf->virt; + buf_end = buf_start + pkt_size; args = (uintptr_t)ctx->buf->virt + metalen; rlen = pkt_size - metalen; ctx->rpra = rpra; @@ -1053,6 +1056,7 @@ static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx) pages[i].size = (pg_end - pg_start + 1) * PAGE_SIZE; } else { + uintptr_t dst; if (ctx->olaps[oix].offset == 0) { rlen -= ALIGN(args, FASTRPC_ALIGN) - args; @@ -1064,7 +1068,18 @@ static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx) if (rlen < mlen) goto bail; - rpra[i].buf.pv = args - ctx->olaps[oix].offset; + if (ctx->olaps[oix].offset > args - buf_start) { + err = -EINVAL; + goto bail; + } + + dst = args - ctx->olaps[oix].offset; + if (len > buf_end - dst) { + err = -EINVAL; + goto bail; + } + rpra[i].buf.pv = dst; + pages[i].addr = ctx->buf->dma_addr - ctx->olaps[oix].offset + (pkt_size - rlen); -- 2.50.1 (Apple Git-155)