btrfs: fix send ioctl on 32bit with 64bit kernel
We pass in a pointer in our send arg struct, this means the struct size
doesn't match with 32bit user space and 64bit kernel space. Fix this by
adding a compat mode and doing the appropriate conversion.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ move structure to the beginning, next to receive 32bit compat ]
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 83ccadaf..f969c03 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -86,6 +86,19 @@ struct btrfs_ioctl_received_subvol_args_32 {
struct btrfs_ioctl_received_subvol_args_32)
#endif
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+struct btrfs_ioctl_send_args_32 {
+ __s64 send_fd; /* in */
+ __u64 clone_sources_count; /* in */
+ compat_uptr_t clone_sources; /* in */
+ __u64 parent_root; /* in */
+ __u64 flags; /* in */
+ __u64 reserved[4]; /* in */
+} __attribute__ ((__packed__));
+
+#define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
+ struct btrfs_ioctl_send_args_32)
+#endif
static int btrfs_clone(struct inode *src, struct inode *inode,
u64 off, u64 olen, u64 olen_aligned, u64 destoff,
@@ -5463,6 +5476,41 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
return ret;
}
+static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
+{
+ struct btrfs_ioctl_send_args *arg;
+ int ret;
+
+ if (compat) {
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+ struct btrfs_ioctl_send_args_32 args32;
+
+ ret = copy_from_user(&args32, argp, sizeof(args32));
+ if (ret)
+ return -EFAULT;
+ arg = kzalloc(sizeof(*arg), GFP_KERNEL);
+ if (!arg)
+ return -ENOMEM;
+ arg->send_fd = args32.send_fd;
+ arg->clone_sources_count = args32.clone_sources_count;
+ arg->clone_sources = compat_ptr(args32.clone_sources);
+ arg->parent_root = args32.parent_root;
+ arg->flags = args32.flags;
+ memcpy(arg->reserved, args32.reserved,
+ sizeof(args32.reserved));
+#else
+ return -ENOTTY;
+#endif
+ } else {
+ arg = memdup_user(argp, sizeof(*arg));
+ if (IS_ERR(arg))
+ return PTR_ERR(arg);
+ }
+ ret = btrfs_ioctl_send(file, arg);
+ kfree(arg);
+ return ret;
+}
+
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
@@ -5568,7 +5616,11 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_set_received_subvol_32(file, argp);
#endif
case BTRFS_IOC_SEND:
- return btrfs_ioctl_send(file, argp);
+ return _btrfs_ioctl_send(file, argp, false);
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+ case BTRFS_IOC_SEND_32:
+ return _btrfs_ioctl_send(file, argp, true);
+#endif
case BTRFS_IOC_GET_DEV_STATS:
return btrfs_ioctl_get_dev_stats(fs_info, argp);
case BTRFS_IOC_QUOTA_CTL: