fix rawctl compat ioctls breakage on amd64 and itanic
Al Viro [Mon, 24 Aug 2009 22:42:56 +0000 (22:42 +0000)]
RAW_SETBIND and RAW_GETBIND 32bit versions are fscked in interesting ways.

1) fs/compat_ioctl.c has COMPATIBLE_IOCTL(RAW_SETBIND) followed by
HANDLE_IOCTL(RAW_SETBIND, raw_ioctl).  The latter is ignored.

2) on amd64 (and itanic) the damn thing is broken - we have int + u64 + u64
and layouts on i386 and amd64 are _not_ the same.  raw_ioctl() would
work there, but it's never called due to (1).  As it is, i386 /sbin/raw
definitely doesn't work on amd64 boxen.

3) switching to raw_ioctl() as is would *not* work on e.g. sparc64 and ppc64,
which would be rather sad, seeing that normal userland there is 32bit.
The thing is, slapping __packed on the struct in question does not DTRT -
it eliminates *all* padding.  The real solution is to use compat_u64.

4) of course, all that stuff has no business being outside of raw.c in the
first place - there should be ->compat_ioctl() for /dev/rawctl instead of
messing with compat_ioctl.c.

[akpm@linux-foundation.org: coding-style fixes]
[arnd@arndb.de: port to 2.6.36]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

drivers/char/raw.c
fs/compat_ioctl.c

index b38942f..24b2b91 100644 (file)
@@ -19,8 +19,8 @@
 #include <linux/cdev.h>
 #include <linux/device.h>
 #include <linux/mutex.h>
-#include <linux/smp_lock.h>
 #include <linux/gfp.h>
+#include <linux/compat.h>
 
 #include <asm/uaccess.h>
 
@@ -55,7 +55,6 @@ static int raw_open(struct inode *inode, struct file *filp)
                return 0;
        }
 
-       lock_kernel();
        mutex_lock(&raw_mutex);
 
        /*
@@ -82,7 +81,6 @@ static int raw_open(struct inode *inode, struct file *filp)
                        bdev->bd_inode->i_mapping;
        filp->private_data = bdev;
        mutex_unlock(&raw_mutex);
-       unlock_kernel();
        return 0;
 
 out2:
@@ -91,7 +89,6 @@ out1:
        blkdev_put(bdev, filp->f_mode);
 out:
        mutex_unlock(&raw_mutex);
-       unlock_kernel();
        return err;
 }
 
@@ -125,20 +122,84 @@ static long
 raw_ioctl(struct file *filp, unsigned int command, unsigned long arg)
 {
        struct block_device *bdev = filp->private_data;
-       int ret;
+       return blkdev_ioctl(bdev, 0, command, arg);
+}
+
+static int bind_set(int number, u64 major, u64 minor)
+{
+       dev_t dev = MKDEV(major, minor);
+       struct raw_device_data *rawdev;
+       int err = 0;
 
-       lock_kernel();
-       ret = blkdev_ioctl(bdev, 0, command, arg);
-       unlock_kernel();
+       if (number <= 0 || number >= MAX_RAW_MINORS)
+               return -EINVAL;
 
-       return ret;
+       if (MAJOR(dev) != major || MINOR(dev) != minor)
+               return -EINVAL;
+
+       rawdev = &raw_devices[number];
+
+       /*
+        * This is like making block devices, so demand the
+        * same capability
+        */
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       /*
+        * For now, we don't need to check that the underlying
+        * block device is present or not: we can do that when
+        * the raw device is opened.  Just check that the
+        * major/minor numbers make sense.
+        */
+
+       if (MAJOR(dev) == 0 && dev != 0)
+               return -EINVAL;
+
+       mutex_lock(&raw_mutex);
+       if (rawdev->inuse) {
+               mutex_unlock(&raw_mutex);
+               return -EBUSY;
+       }
+       if (rawdev->binding) {
+               bdput(rawdev->binding);
+               module_put(THIS_MODULE);
+       }
+       if (!dev) {
+               /* unbind */
+               rawdev->binding = NULL;
+               device_destroy(raw_class, MKDEV(RAW_MAJOR, number));
+       } else {
+               rawdev->binding = bdget(dev);
+               if (rawdev->binding == NULL) {
+                       err = -ENOMEM;
+               } else {
+                       dev_t raw = MKDEV(RAW_MAJOR, number);
+                       __module_get(THIS_MODULE);
+                       device_destroy(raw_class, raw);
+                       device_create(raw_class, NULL, raw, NULL,
+                                     "raw%d", number);
+               }
+       }
+       mutex_unlock(&raw_mutex);
+       return err;
 }
 
-static void bind_device(struct raw_config_request *rq)
+static int bind_get(int number, dev_t *dev)
 {
-       device_destroy(raw_class, MKDEV(RAW_MAJOR, rq->raw_minor));
-       device_create(raw_class, NULL, MKDEV(RAW_MAJOR, rq->raw_minor), NULL,
-                     "raw%d", rq->raw_minor);
+       struct raw_device_data *rawdev;
+       struct block_device *bdev;
+
+       if (number <= 0 || number >= MAX_RAW_MINORS)
+               return -EINVAL;
+
+       rawdev = &raw_devices[number];
+
+       mutex_lock(&raw_mutex);
+       bdev = rawdev->binding;
+       *dev = bdev ? bdev->bd_dev : 0;
+       mutex_unlock(&raw_mutex);
+       return 0;
 }
 
 /*
@@ -149,105 +210,78 @@ static long raw_ctl_ioctl(struct file *filp, unsigned int command,
                          unsigned long arg)
 {
        struct raw_config_request rq;
-       struct raw_device_data *rawdev;
-       int err = 0;
+       dev_t dev;
+       int err;
 
-       lock_kernel();
        switch (command) {
        case RAW_SETBIND:
+               if (copy_from_user(&rq, (void __user *) arg, sizeof(rq)))
+                       return -EFAULT;
+
+               return bind_set(rq.raw_minor, rq.block_major, rq.block_minor);
+
        case RAW_GETBIND:
+               if (copy_from_user(&rq, (void __user *) arg, sizeof(rq)))
+                       return -EFAULT;
 
-               /* First, find out which raw minor we want */
+               err = bind_get(rq.raw_minor, &dev);
+               if (err)
+                       return err;
 
-               if (copy_from_user(&rq, (void __user *) arg, sizeof(rq))) {
-                       err = -EFAULT;
-                       goto out;
-               }
+               rq.block_major = MAJOR(dev);
+               rq.block_minor = MINOR(dev);
 
-               if (rq.raw_minor <= 0 || rq.raw_minor >= MAX_RAW_MINORS) {
-                       err = -EINVAL;
-                       goto out;
-               }
-               rawdev = &raw_devices[rq.raw_minor];
-
-               if (command == RAW_SETBIND) {
-                       dev_t dev;
-
-                       /*
-                        * This is like making block devices, so demand the
-                        * same capability
-                        */
-                       if (!capable(CAP_SYS_ADMIN)) {
-                               err = -EPERM;
-                               goto out;
-                       }
-
-                       /*
-                        * For now, we don't need to check that the underlying
-                        * block device is present or not: we can do that when
-                        * the raw device is opened.  Just check that the
-                        * major/minor numbers make sense.
-                        */
-
-                       dev = MKDEV(rq.block_major, rq.block_minor);
-                       if ((rq.block_major == 0 && rq.block_minor != 0) ||
-                                       MAJOR(dev) != rq.block_major ||
-                                       MINOR(dev) != rq.block_minor) {
-                               err = -EINVAL;
-                               goto out;
-                       }
-
-                       mutex_lock(&raw_mutex);
-                       if (rawdev->inuse) {
-                               mutex_unlock(&raw_mutex);
-                               err = -EBUSY;
-                               goto out;
-                       }
-                       if (rawdev->binding) {
-                               bdput(rawdev->binding);
-                               module_put(THIS_MODULE);
-                       }
-                       if (rq.block_major == 0 && rq.block_minor == 0) {
-                               /* unbind */
-                               rawdev->binding = NULL;
-                               device_destroy(raw_class,
-                                               MKDEV(RAW_MAJOR, rq.raw_minor));
-                       } else {
-                               rawdev->binding = bdget(dev);
-                               if (rawdev->binding == NULL)
-                                       err = -ENOMEM;
-                               else {
-                                       __module_get(THIS_MODULE);
-                                       bind_device(&rq);
-                               }
-                       }
-                       mutex_unlock(&raw_mutex);
-               } else {
-                       struct block_device *bdev;
-
-                       mutex_lock(&raw_mutex);
-                       bdev = rawdev->binding;
-                       if (bdev) {
-                               rq.block_major = MAJOR(bdev->bd_dev);
-                               rq.block_minor = MINOR(bdev->bd_dev);
-                       } else {
-                               rq.block_major = rq.block_minor = 0;
-                       }
-                       mutex_unlock(&raw_mutex);
-                       if (copy_to_user((void __user *)arg, &rq, sizeof(rq))) {
-                               err = -EFAULT;
-                               goto out;
-                       }
-               }
-               break;
-       default:
-               err = -EINVAL;
-               break;
+               if (copy_to_user((void __user *)arg, &rq, sizeof(rq)))
+                       return -EFAULT;
+
+               return 0;
        }
-out:
-       unlock_kernel();
-       return err;
+
+       return -EINVAL;
+}
+
+#ifdef CONFIG_COMPAT
+struct raw32_config_request {
+       compat_int_t    raw_minor;
+       compat_u64      block_major;
+       compat_u64      block_minor;
+};
+
+static long raw_ctl_compat_ioctl(struct file *file, unsigned int cmd,
+                               unsigned long arg)
+{
+       struct raw32_config_request __user *user_req = compat_ptr(arg);
+       struct raw32_config_request rq;
+       dev_t dev;
+       int err = 0;
+
+       switch (cmd) {
+       case RAW_SETBIND:
+               if (copy_from_user(&rq, user_req, sizeof(rq)))
+                       return -EFAULT;
+
+               return bind_set(rq.raw_minor, rq.block_major, rq.block_minor);
+
+       case RAW_GETBIND:
+               if (copy_from_user(&rq, user_req, sizeof(rq)))
+                       return -EFAULT;
+
+               err = bind_get(rq.raw_minor, &dev);
+               if (err)
+                       return err;
+
+               rq.block_major = MAJOR(dev);
+               rq.block_minor = MINOR(dev);
+
+               if (copy_to_user(user_req, &rq, sizeof(rq)))
+                       return -EFAULT;
+
+               return 0;
+       }
+
+       return -EINVAL;
 }
+#endif
 
 static const struct file_operations raw_fops = {
        .read           = do_sync_read,
@@ -263,6 +297,9 @@ static const struct file_operations raw_fops = {
 
 static const struct file_operations raw_ctl_fops = {
        .unlocked_ioctl = raw_ctl_ioctl,
+#ifdef CONFIG_COMPAT
+       .compat_ioctl   = raw_ctl_compat_ioctl,
+#endif
        .open           = raw_open,
        .owner          = THIS_MODULE,
 };
index 03e59aa..d0ad09d 100644 (file)
@@ -599,69 +599,6 @@ static int do_smb_getmountuid(unsigned int fd, unsigned int cmd,
 #define HIDPGETCONNLIST        _IOR('H', 210, int)
 #define HIDPGETCONNINFO        _IOR('H', 211, int)
 
-#ifdef CONFIG_BLOCK
-struct raw32_config_request
-{
-        compat_int_t    raw_minor;
-        __u64   block_major;
-        __u64   block_minor;
-} __attribute__((packed));
-
-static int get_raw32_request(struct raw_config_request *req, struct raw32_config_request __user *user_req)
-{
-        int ret;
-
-        if (!access_ok(VERIFY_READ, user_req, sizeof(struct raw32_config_request)))
-                return -EFAULT;
-
-        ret = __get_user(req->raw_minor, &user_req->raw_minor);
-        ret |= __get_user(req->block_major, &user_req->block_major);
-        ret |= __get_user(req->block_minor, &user_req->block_minor);
-
-        return ret ? -EFAULT : 0;
-}
-
-static int set_raw32_request(struct raw_config_request *req, struct raw32_config_request __user *user_req)
-{
-       int ret;
-
-        if (!access_ok(VERIFY_WRITE, user_req, sizeof(struct raw32_config_request)))
-                return -EFAULT;
-
-        ret = __put_user(req->raw_minor, &user_req->raw_minor);
-        ret |= __put_user(req->block_major, &user_req->block_major);
-        ret |= __put_user(req->block_minor, &user_req->block_minor);
-
-        return ret ? -EFAULT : 0;
-}
-
-static int raw_ioctl(unsigned fd, unsigned cmd,
-               struct raw32_config_request __user *user_req)
-{
-        int ret;
-
-        switch (cmd) {
-        case RAW_SETBIND:
-       default: {      /* RAW_GETBIND */
-                struct raw_config_request req;
-                mm_segment_t oldfs = get_fs();
-
-                if ((ret = get_raw32_request(&req, user_req)))
-                        return ret;
-
-                set_fs(KERNEL_DS);
-                ret = sys_ioctl(fd,cmd,(unsigned long)&req);
-                set_fs(oldfs);
-
-                if ((!ret) && (cmd == RAW_GETBIND)) {
-                        ret = set_raw32_request(&req, user_req);
-                }
-                break;
-        }
-        }
-        return ret;
-}
-#endif /* CONFIG_BLOCK */
 
 struct serial_struct32 {
         compat_int_t    type;
@@ -1262,9 +1199,6 @@ COMPATIBLE_IOCTL(SOUND_MIXER_PRIVATE5)
 COMPATIBLE_IOCTL(SOUND_MIXER_GETLEVELS)
 COMPATIBLE_IOCTL(SOUND_MIXER_SETLEVELS)
 COMPATIBLE_IOCTL(OSS_GETVERSION)
-/* Raw devices */
-COMPATIBLE_IOCTL(RAW_SETBIND)
-COMPATIBLE_IOCTL(RAW_GETBIND)
 /* SMB ioctls which do not need any translations */
 COMPATIBLE_IOCTL(SMB_IOC_NEWCONN)
 /* Watchdog */
@@ -1523,10 +1457,6 @@ static long do_ioctl_trans(int fd, unsigned int cmd,
        case MTIOCGET32:
        case MTIOCPOS32:
                return mt_ioctl_trans(fd, cmd, argp);
-       /* Raw devices */
-       case RAW_SETBIND:
-       case RAW_GETBIND:
-               return raw_ioctl(fd, cmd, argp);
 #endif
        /* One SMB ioctl needs translations. */
 #define SMB_IOC_GETMOUNTUID_32 _IOR('u', 1, compat_uid_t)