Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753960Ab2JPKt0 (ORCPT ); Tue, 16 Oct 2012 06:49:26 -0400 Received: from mail-lb0-f174.google.com ([209.85.217.174]:64003 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753580Ab2JPKtY (ORCPT ); Tue, 16 Oct 2012 06:49:24 -0400 MIME-Version: 1.0 In-Reply-To: <1350376988-27477-1-git-send-email-james.hogan@imgtec.com> References: <1350376988-27477-1-git-send-email-james.hogan@imgtec.com> Date: Tue, 16 Oct 2012 16:19:23 +0530 Message-ID: Subject: Re: [PATCH] dw_mmc: fix multiple drv_data NULL dereferences From: Thomas Abraham To: James Hogan Cc: Chris Ball , Will Newton , Jaehoon Chung , Seungwon Jeon , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6281 Lines: 153 On 16 October 2012 14:13, James Hogan wrote: > Commit 800d78bfccb3d38116abfda2a5b9c8afdbd5ea21 ("mmc: dw_mmc: add > support for implementation specific callbacks") merged in v3.7-rc1. > > The above commit introduced multiple NULL pointer dereferences when > the default dw_mci_pltfm_probe() is used, as it sets host->drv_data to > NULL, and that's only checked against NULL in 1 out of the 7 cases where > it is dereferenced. > > Signed-off-by: James Hogan > --- > drivers/mmc/host/dw_mmc-pltfm.c | 4 ++-- > drivers/mmc/host/dw_mmc.c | 29 +++++++++++++++++------------ > 2 files changed, 19 insertions(+), 14 deletions(-) > > diff --git a/drivers/mmc/host/dw_mmc-pltfm.c b/drivers/mmc/host/dw_mmc-pltfm.c > index c960ca7..e595721 100644 > --- a/drivers/mmc/host/dw_mmc-pltfm.c > +++ b/drivers/mmc/host/dw_mmc-pltfm.c > @@ -50,8 +50,8 @@ int dw_mci_pltfm_register(struct platform_device *pdev, > if (!host->regs) > return -ENOMEM; > > - if (host->drv_data->init) { > - ret = host->drv_data->init(host); > + if (drv_data && drv_data->init) { > + ret = drv_data->init(host); > if (ret) > return ret; > } > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index c2828f3..0dc6e33 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -232,6 +232,7 @@ static u32 dw_mci_prepare_command(struct mmc_host *mmc, struct mmc_command *cmd) > { > struct mmc_data *data; > struct dw_mci_slot *slot = mmc_priv(mmc); > + struct dw_mci_drv_data *drv_data = slot->host->drv_data; > u32 cmdr; > cmd->error = -EINPROGRESS; > > @@ -261,8 +262,8 @@ static u32 dw_mci_prepare_command(struct mmc_host *mmc, struct mmc_command *cmd) > cmdr |= SDMMC_CMD_DAT_WR; > } > > - if (slot->host->drv_data->prepare_command) > - slot->host->drv_data->prepare_command(slot->host, &cmdr); > + if (drv_data && drv_data->prepare_command) > + drv_data->prepare_command(slot->host, &cmdr); > > return cmdr; > } > @@ -772,6 +773,7 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq) > static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) > { > struct dw_mci_slot *slot = mmc_priv(mmc); > + struct dw_mci_drv_data *drv_data = slot->host->drv_data; > u32 regs; > > /* set default 1 bit mode */ > @@ -807,8 +809,8 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) > slot->clock = ios->clock; > } > > - if (slot->host->drv_data->set_ios) > - slot->host->drv_data->set_ios(slot->host, ios); > + if (drv_data && drv_data->set_ios) > + drv_data->set_ios(slot->host, ios); > > switch (ios->power_mode) { > case MMC_POWER_UP: > @@ -1815,6 +1817,7 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id) > { > struct mmc_host *mmc; > struct dw_mci_slot *slot; > + struct dw_mci_drv_data *drv_data = host->drv_data; > int ctrl_id, ret; > u8 bus_width; > > @@ -1854,8 +1857,8 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id) > } else { > ctrl_id = to_platform_device(host->dev)->id; > } > - if (host->drv_data && host->drv_data->caps) > - mmc->caps |= host->drv_data->caps[ctrl_id]; > + if (drv_data && drv_data->caps) > + mmc->caps |= drv_data->caps[ctrl_id]; > > if (host->pdata->caps2) > mmc->caps2 = host->pdata->caps2; > @@ -1867,10 +1870,10 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id) > else > bus_width = 1; > > - if (host->drv_data->setup_bus) { > + if (drv_data && drv_data->setup_bus) { > struct device_node *slot_np; > slot_np = dw_mci_of_find_slot_node(host->dev, slot->id); > - ret = host->drv_data->setup_bus(host, slot_np, bus_width); > + ret = drv_data->setup_bus(host, slot_np, bus_width); > if (ret) > goto err_setup_bus; > } > @@ -2035,6 +2038,7 @@ static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host) > struct dw_mci_board *pdata; > struct device *dev = host->dev; > struct device_node *np = dev->of_node; > + struct dw_mci_drv_data *drv_data = host->drv_data; > int idx, ret; > > pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); > @@ -2062,8 +2066,8 @@ static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host) > > of_property_read_u32(np, "card-detect-delay", &pdata->detect_delay_ms); > > - if (host->drv_data->parse_dt) { > - ret = host->drv_data->parse_dt(host); > + if (drv_data && drv_data->parse_dt) { > + ret = drv_data->parse_dt(host); > if (ret) > return ERR_PTR(ret); > } > @@ -2080,6 +2084,7 @@ static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host) > > int dw_mci_probe(struct dw_mci *host) > { > + struct dw_mci_drv_data *drv_data = host->drv_data; > int width, i, ret = 0; > u32 fifo_size; > int init_slots = 0; > @@ -2127,8 +2132,8 @@ int dw_mci_probe(struct dw_mci *host) > else > host->bus_hz = clk_get_rate(host->ciu_clk); > > - if (host->drv_data->setup_clock) { > - ret = host->drv_data->setup_clock(host); > + if (drv_data && drv_data->setup_clock) { > + ret = drv_data->setup_clock(host); > if (ret) { > dev_err(host->dev, > "implementation specific clock setup failed\n"); > -- > 1.7.7.6 > > Acked-by: Thomas Abraham -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/