From f1c2e33c295de423db5740647bfaa5e2ad139192 Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Wed, 11 Aug 2010 18:20:55 +0200 Subject: i2c-dev: Use memdup_user Use memdup_user when user data is immediately copied into the allocated region. Note that in the second case, the ++i is no longer necessary, as the last value is already freed if needed by the call to memdup_user. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // @@ expression from,to,size,flag; position p; identifier l1,l2; @@ - to = \(kmalloc@p\|kzalloc@p\)(size,flag); + to = memdup_user(from,size); if ( - to==NULL + IS_ERR(to) || ...) { <+... when != goto l1; - -ENOMEM + PTR_ERR(to) ...+> } - if (copy_from_user(to, from, size) != 0) { - <+... when != goto l2; - -EFAULT - ...+> - } // Signed-off-by: Julia Lawall Signed-off-by: Jean Delvare --- drivers/i2c/i2c-dev.c | 22 ++++++---------------- 1 file changed, 6 insertions(+), 16 deletions(-) (limited to 'drivers/i2c/i2c-dev.c') diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index b3fcb59a5a1..0b0427f7d34 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -167,13 +167,9 @@ static ssize_t i2cdev_write(struct file *file, const char __user *buf, if (count > 8192) count = 8192; - tmp = kmalloc(count, GFP_KERNEL); - if (tmp == NULL) - return -ENOMEM; - if (copy_from_user(tmp, buf, count)) { - kfree(tmp); - return -EFAULT; - } + tmp = memdup_user(buf, count); + if (IS_ERR(tmp)) + return PTR_ERR(tmp); pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n", iminor(file->f_path.dentry->d_inode), count); @@ -245,15 +241,9 @@ static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client, break; } data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; - rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL); - if (rdwr_pa[i].buf == NULL) { - res = -ENOMEM; - break; - } - if (copy_from_user(rdwr_pa[i].buf, data_ptrs[i], - rdwr_pa[i].len)) { - ++i; /* Needs to be kfreed too */ - res = -EFAULT; + rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len); + if (IS_ERR(rdwr_pa[i].buf)) { + res = PTR_ERR(rdwr_pa[i].buf); break; } } -- cgit v1.2.3-70-g09d2