From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Motyka Date: Mon, 09 May 2011 20:37:40 +0000 Subject: Re: [PATCH] drivers/mmc/card/block.c: fix potential null dereference Message-Id: <4DC85094.4050401@gmail.com> List-Id: References: <4DC7F4AB.90607@gmail.com> <4DC802C0.9040302@gmail.com> <4DC8117C.7060200@gmail.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Julia Lawall Cc: cjb@laptop.org, kernel-janitors@vger.kernel.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org When allocation of idata failed there was a null dereference. Also avoid calling kfree where it is needn't. --- diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 407836d..126c7f4 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -237,24 +237,24 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user( idata = kzalloc(sizeof(*idata), GFP_KERNEL); if (!idata) { err = -ENOMEM; - goto copy_err; + goto out; } if (copy_from_user(&idata->ic, user, sizeof(idata->ic))) { err = -EFAULT; - goto copy_err; + goto idata_err; } idata->buf_bytes = (u64) idata->ic.blksz * idata->ic.blocks; if (idata->buf_bytes > MMC_IOC_MAX_BYTES) { err = -EOVERFLOW; - goto copy_err; + goto idata_err; } idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL); if (!idata->buf) { err = -ENOMEM; - goto copy_err; + goto idata_err; } if (copy_from_user(idata->buf, (void __user *)(unsigned long) @@ -267,9 +267,10 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user( copy_err: kfree(idata->buf); +idata_err: kfree(idata); +out: return ERR_PTR(err); - } static int mmc_blk_ioctl_cmd(struct block_device *bdev,