From nobody Sun Apr 5 18:11:20 2026 Received: from cstnet.cn (smtp25.cstnet.cn [159.226.251.25]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4A34B37AA88; Tue, 24 Mar 2026 01:45:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.25 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774316709; cv=none; b=ALoLH2mb7C+SxD3y+iAWWp7NkRbN0w0hVKOQXBaAC4bPAN8CRDQ6mLmI/4JhqFK7cAiYfti7norFRq4DtR811RYRMw2boqACnWph5qltNgMkjEkHMZ/R8o7bZMwLMd2jtIFPDRYF/M/K3S95AR8S+oJcTu+9ljRlRXfok/cGpYk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774316709; c=relaxed/simple; bh=WEHfF09gxCh5Q1vtD/pbxEgYQPZBD20Ph8r8G98rdbg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=YCDoIcVBQi3wHifIHAZIT77p98LjGr9e644yMQQIBB+Xa7DM4ZOlHyPw6Toq5kmxu+1EzPwzrvPCVWXST3mQmTQivpvtU/rrgF+4sWzOoTwSBgB3rTVlO9K1I9Hl+lyt+YdDSiK03R0dBXyTk0wVGaWb304wHeyH0Fz66btgAFs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.25 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn 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 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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-CM-SenderInfo: pshqw1xhqjqxpvfd2hldfou0/ Content-Type: text/plain; charset="utf-8" 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; =20 inbufs =3D REMOTE_SCALARS_INBUFS(ctx->sc); @@ -1016,6 +1017,8 @@ static int fastrpc_get_args(u32 kernel, struct fastrp= c_invoke_ctx *ctx) rpra =3D ctx->buf->virt; list =3D fastrpc_invoke_buf_start(rpra, ctx->nscalars); pages =3D fastrpc_phy_page_start(list, ctx->nscalars); + buf_start =3D (uintptr_t)ctx->buf->virt; + buf_end =3D buf_start + pkt_size; args =3D (uintptr_t)ctx->buf->virt + metalen; rlen =3D pkt_size - metalen; ctx->rpra =3D rpra; @@ -1053,6 +1056,7 @@ static int fastrpc_get_args(u32 kernel, struct fastrp= c_invoke_ctx *ctx) pages[i].size =3D (pg_end - pg_start + 1) * PAGE_SIZE; =20 } else { + uintptr_t dst; =20 if (ctx->olaps[oix].offset =3D=3D 0) { rlen -=3D ALIGN(args, FASTRPC_ALIGN) - args; @@ -1064,7 +1068,18 @@ static int fastrpc_get_args(u32 kernel, struct fastr= pc_invoke_ctx *ctx) if (rlen < mlen) goto bail; =20 - rpra[i].buf.pv =3D args - ctx->olaps[oix].offset; + if (ctx->olaps[oix].offset > args - buf_start) { + err =3D -EINVAL; + goto bail; + } + + dst =3D args - ctx->olaps[oix].offset; + if (len > buf_end - dst) { + err =3D -EINVAL; + goto bail; + } + rpra[i].buf.pv =3D dst; + pages[i].addr =3D ctx->buf->dma_addr - ctx->olaps[oix].offset + (pkt_size - rlen); --=20 2.50.1 (Apple Git-155)