From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sean Paul Subject: Re: [PATCH v3 06/24] drm/rockchip: dw-mipi-dsi: avoid out-of-bounds read on tx_buf Date: Mon, 30 Jan 2017 13:01:46 -0500 Message-ID: <20170130180146.GG20076@art_vandelay> References: <20170129132444.25251-1-john@metanate.com> <20170129132444.25251-7-john@metanate.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <20170129132444.25251-7-john@metanate.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: John Keeping Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-rockchip@lists.infradead.org, Chris Zhong , linux-arm-kernel@lists.infradead.org List-Id: linux-rockchip.vger.kernel.org T24gU3VuLCBKYW4gMjksIDIwMTcgYXQgMDE6MjQ6MjZQTSArMDAwMCwgSm9obiBLZWVwaW5nIHdy b3RlOgo+IEFzIGEgc2lkZS1lZmZlY3Qgb2YgdGhpcywgZW5jb2RlIHRoZSBlbmRpYW5uZXNzIGV4 cGxpY2l0bHkgcmF0aGVyIHRoYW4KPiBjYXN0aW5nIGEgdTE2Lgo+IAo+IFNpZ25lZC1vZmYtYnk6 IEpvaG4gS2VlcGluZyA8am9obkBtZXRhbmF0ZS5jb20+Cj4gUmV2aWV3ZWQtYnk6IENocmlzIFpo b25nIDx6eXdAcm9jay1jaGlwcy5jb20+Cj4gLS0tCj4gdjM6Cj4gLSBBZGQgQ2hyaXMnIFJldmll d2VkLWJ5Cj4gVW5jaGFuZ2VkIGluIHYyCj4gCj4gIGRyaXZlcnMvZ3B1L2RybS9yb2NrY2hpcC9k dy1taXBpLWRzaS5jIHwgOSArKysrKysrLS0KPiAgMSBmaWxlIGNoYW5nZWQsIDcgaW5zZXJ0aW9u cygrKSwgMiBkZWxldGlvbnMoLSkKPiAKPiBkaWZmIC0tZ2l0IGEvZHJpdmVycy9ncHUvZHJtL3Jv Y2tjaGlwL2R3LW1pcGktZHNpLmMgYi9kcml2ZXJzL2dwdS9kcm0vcm9ja2NoaXAvZHctbWlwaS1k c2kuYwo+IGluZGV4IDRiZTFmZjNhNDJiYi4uMmU2YWQ0NTkxZWJmIDEwMDY0NAo+IC0tLSBhL2Ry aXZlcnMvZ3B1L2RybS9yb2NrY2hpcC9kdy1taXBpLWRzaS5jCj4gKysrIGIvZHJpdmVycy9ncHUv ZHJtL3JvY2tjaGlwL2R3LW1pcGktZHNpLmMKPiBAQCAtNTcyLDggKzU3MiwxMyBAQCBzdGF0aWMg aW50IGR3X21pcGlfZHNpX2dlbl9wa3RfaGRyX3dyaXRlKHN0cnVjdCBkd19taXBpX2RzaSAqZHNp LCB1MzIgaGRyX3ZhbCkKPiAgc3RhdGljIGludCBkd19taXBpX2RzaV9kY3Nfc2hvcnRfd3JpdGUo c3RydWN0IGR3X21pcGlfZHNpICpkc2ksCj4gIAkJCQkgICAgICAgY29uc3Qgc3RydWN0IG1pcGlf ZHNpX21zZyAqbXNnKQo+ICB7Cj4gLQljb25zdCB1MTYgKnR4X2J1ZiA9IG1zZy0+dHhfYnVmOwo+ IC0JdTMyIHZhbCA9IEdFTl9IREFUQSgqdHhfYnVmKSB8IEdFTl9IVFlQRShtc2ctPnR5cGUpOwo+ ICsJY29uc3QgdTggKnR4X2J1ZiA9IG1zZy0+dHhfYnVmOwo+ICsJdTMyIHZhbCA9IEdFTl9IVFlQ RShtc2ctPnR5cGUpOwo+ICsKPiArCWlmIChtc2ctPnR4X2xlbiA+IDApCj4gKwkJdmFsIHw9IEdF Tl9IREFUQSh0eF9idWZbMF0pOwo+ICsJaWYgKG1zZy0+dHhfbGVuID4gMSkKPiArCQl2YWwgfD0g R0VOX0hEQVRBKHR4X2J1ZlsxXSA8PCA4KTsKCllvdSBzaG91bGQgcHJvYmFibHkgdXBkYXRlIHRo ZSBtYXNrIGluc2lkZSBHRU5fSERBVEEgdG8gbWFzayBvZmYgOCBiaXRzIGluc3RlYWQgb2YKMTYu CgpTZWFuCgo+ICAKPiAgCWlmIChtc2ctPnR4X2xlbiA+IDIpIHsKPiAgCQlkZXZfZXJyKGRzaS0+ ZGV2LCAidG9vIGxvbmcgdHggYnVmIGxlbmd0aCAlenUgZm9yIHNob3J0IHdyaXRlXG4iLAo+IC0t IAo+IDIuMTEuMC4xOTcuZ2I1NTZkZTUuZGlydHkKPiAKPiBfX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fXwo+IGRyaS1kZXZlbCBtYWlsaW5nIGxpc3QKPiBkcmkt ZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCj4gaHR0cHM6Ly9saXN0cy5mcmVlZGVza3RvcC5v cmcvbWFpbG1hbi9saXN0aW5mby9kcmktZGV2ZWwKCi0tIApTZWFuIFBhdWwsIFNvZnR3YXJlIEVu Z2luZWVyLCBHb29nbGUgLyBDaHJvbWl1bSBPUwpfX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fXwpkcmktZGV2ZWwgbWFpbGluZyBsaXN0CmRyaS1kZXZlbEBsaXN0 cy5mcmVlZGVza3RvcC5vcmcKaHR0cHM6Ly9saXN0cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1hbi9s aXN0aW5mby9kcmktZGV2ZWwK From mboxrd@z Thu Jan 1 00:00:00 1970 From: seanpaul@chromium.org (Sean Paul) Date: Mon, 30 Jan 2017 13:01:46 -0500 Subject: [PATCH v3 06/24] drm/rockchip: dw-mipi-dsi: avoid out-of-bounds read on tx_buf In-Reply-To: <20170129132444.25251-7-john@metanate.com> References: <20170129132444.25251-1-john@metanate.com> <20170129132444.25251-7-john@metanate.com> Message-ID: <20170130180146.GG20076@art_vandelay> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sun, Jan 29, 2017 at 01:24:26PM +0000, John Keeping wrote: > As a side-effect of this, encode the endianness explicitly rather than > casting a u16. > > Signed-off-by: John Keeping > Reviewed-by: Chris Zhong > --- > v3: > - Add Chris' Reviewed-by > Unchanged in v2 > > drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > index 4be1ff3a42bb..2e6ad4591ebf 100644 > --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > @@ -572,8 +572,13 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val) > static int dw_mipi_dsi_dcs_short_write(struct dw_mipi_dsi *dsi, > const struct mipi_dsi_msg *msg) > { > - const u16 *tx_buf = msg->tx_buf; > - u32 val = GEN_HDATA(*tx_buf) | GEN_HTYPE(msg->type); > + const u8 *tx_buf = msg->tx_buf; > + u32 val = GEN_HTYPE(msg->type); > + > + if (msg->tx_len > 0) > + val |= GEN_HDATA(tx_buf[0]); > + if (msg->tx_len > 1) > + val |= GEN_HDATA(tx_buf[1] << 8); You should probably update the mask inside GEN_HDATA to mask off 8 bits instead of 16. Sean > > if (msg->tx_len > 2) { > dev_err(dsi->dev, "too long tx buf length %zu for short write\n", > -- > 2.11.0.197.gb556de5.dirty > > _______________________________________________ > dri-devel mailing list > dri-devel at lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Sean Paul, Software Engineer, Google / Chromium OS From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753860AbdA3SBu (ORCPT ); Mon, 30 Jan 2017 13:01:50 -0500 Received: from mail-qt0-f180.google.com ([209.85.216.180]:32776 "EHLO mail-qt0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752154AbdA3SBt (ORCPT ); Mon, 30 Jan 2017 13:01:49 -0500 Date: Mon, 30 Jan 2017 13:01:46 -0500 From: Sean Paul To: John Keeping Cc: Mark Yao , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-rockchip@lists.infradead.org, Chris Zhong , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v3 06/24] drm/rockchip: dw-mipi-dsi: avoid out-of-bounds read on tx_buf Message-ID: <20170130180146.GG20076@art_vandelay> References: <20170129132444.25251-1-john@metanate.com> <20170129132444.25251-7-john@metanate.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170129132444.25251-7-john@metanate.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jan 29, 2017 at 01:24:26PM +0000, John Keeping wrote: > As a side-effect of this, encode the endianness explicitly rather than > casting a u16. > > Signed-off-by: John Keeping > Reviewed-by: Chris Zhong > --- > v3: > - Add Chris' Reviewed-by > Unchanged in v2 > > drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > index 4be1ff3a42bb..2e6ad4591ebf 100644 > --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > @@ -572,8 +572,13 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val) > static int dw_mipi_dsi_dcs_short_write(struct dw_mipi_dsi *dsi, > const struct mipi_dsi_msg *msg) > { > - const u16 *tx_buf = msg->tx_buf; > - u32 val = GEN_HDATA(*tx_buf) | GEN_HTYPE(msg->type); > + const u8 *tx_buf = msg->tx_buf; > + u32 val = GEN_HTYPE(msg->type); > + > + if (msg->tx_len > 0) > + val |= GEN_HDATA(tx_buf[0]); > + if (msg->tx_len > 1) > + val |= GEN_HDATA(tx_buf[1] << 8); You should probably update the mask inside GEN_HDATA to mask off 8 bits instead of 16. Sean > > if (msg->tx_len > 2) { > dev_err(dsi->dev, "too long tx buf length %zu for short write\n", > -- > 2.11.0.197.gb556de5.dirty > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Sean Paul, Software Engineer, Google / Chromium OS