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-rw-r--r--fs/btrfs/ioctl.c147
1 files changed, 121 insertions, 26 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 82c18ba12e3f..0d321c23069a 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1957,7 +1957,8 @@ static noinline int copy_to_sk(struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_key *key,
struct btrfs_ioctl_search_key *sk,
- char *buf,
+ size_t *buf_size,
+ char __user *ubuf,
unsigned long *sk_offset,
int *num_found)
{
@@ -1989,13 +1990,25 @@ static noinline int copy_to_sk(struct btrfs_root *root,
if (!key_in_sk(key, sk))
continue;
- if (sizeof(sh) + item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
+ if (sizeof(sh) + item_len > *buf_size) {
+ if (*num_found) {
+ ret = 1;
+ goto out;
+ }
+
+ /*
+ * return one empty item back for v1, which does not
+ * handle -EOVERFLOW
+ */
+
+ *buf_size = sizeof(sh) + item_len;
item_len = 0;
+ ret = -EOVERFLOW;
+ }
- if (sizeof(sh) + item_len + *sk_offset >
- BTRFS_SEARCH_ARGS_BUFSIZE) {
+ if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
ret = 1;
- goto overflow;
+ goto out;
}
sh.objectid = key->objectid;
@@ -2005,20 +2018,33 @@ static noinline int copy_to_sk(struct btrfs_root *root,
sh.transid = found_transid;
/* copy search result header */
- memcpy(buf + *sk_offset, &sh, sizeof(sh));
+ if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
+ ret = -EFAULT;
+ goto out;
+ }
+
*sk_offset += sizeof(sh);
if (item_len) {
- char *p = buf + *sk_offset;
+ char __user *up = ubuf + *sk_offset;
/* copy the item */
- read_extent_buffer(leaf, p,
- item_off, item_len);
+ if (read_extent_buffer_to_user(leaf, up,
+ item_off, item_len)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
*sk_offset += item_len;
}
(*num_found)++;
- if (*num_found >= sk->nr_items)
- break;
+ if (ret) /* -EOVERFLOW from above */
+ goto out;
+
+ if (*num_found >= sk->nr_items) {
+ ret = 1;
+ goto out;
+ }
}
advance_key:
ret = 0;
@@ -2033,22 +2059,37 @@ advance_key:
key->objectid++;
} else
ret = 1;
-overflow:
+out:
+ /*
+ * 0: all items from this leaf copied, continue with next
+ * 1: * more items can be copied, but unused buffer is too small
+ * * all items were found
+ * Either way, it will stops the loop which iterates to the next
+ * leaf
+ * -EOVERFLOW: item was to large for buffer
+ * -EFAULT: could not copy extent buffer back to userspace
+ */
return ret;
}
static noinline int search_ioctl(struct inode *inode,
- struct btrfs_ioctl_search_args *args)
+ struct btrfs_ioctl_search_key *sk,
+ size_t *buf_size,
+ char __user *ubuf)
{
struct btrfs_root *root;
struct btrfs_key key;
struct btrfs_path *path;
- struct btrfs_ioctl_search_key *sk = &args->key;
struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
int ret;
int num_found = 0;
unsigned long sk_offset = 0;
+ if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
+ *buf_size = sizeof(struct btrfs_ioctl_search_header);
+ return -EOVERFLOW;
+ }
+
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
@@ -2082,14 +2123,15 @@ static noinline int search_ioctl(struct inode *inode,
ret = 0;
goto err;
}
- ret = copy_to_sk(root, path, &key, sk, args->buf,
+ ret = copy_to_sk(root, path, &key, sk, buf_size, ubuf,
&sk_offset, &num_found);
btrfs_release_path(path);
- if (ret || num_found >= sk->nr_items)
+ if (ret)
break;
}
- ret = 0;
+ if (ret > 0)
+ ret = 0;
err:
sk->nr_items = num_found;
btrfs_free_path(path);
@@ -2099,22 +2141,73 @@ err:
static noinline int btrfs_ioctl_tree_search(struct file *file,
void __user *argp)
{
- struct btrfs_ioctl_search_args *args;
- struct inode *inode;
- int ret;
+ struct btrfs_ioctl_search_args __user *uargs;
+ struct btrfs_ioctl_search_key sk;
+ struct inode *inode;
+ int ret;
+ size_t buf_size;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- args = memdup_user(argp, sizeof(*args));
- if (IS_ERR(args))
- return PTR_ERR(args);
+ uargs = (struct btrfs_ioctl_search_args __user *)argp;
+
+ if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
+ return -EFAULT;
+
+ buf_size = sizeof(uargs->buf);
inode = file_inode(file);
- ret = search_ioctl(inode, args);
- if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
+ ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
+
+ /*
+ * In the origin implementation an overflow is handled by returning a
+ * search header with a len of zero, so reset ret.
+ */
+ if (ret == -EOVERFLOW)
+ ret = 0;
+
+ if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
ret = -EFAULT;
- kfree(args);
+ return ret;
+}
+
+static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
+ void __user *argp)
+{
+ struct btrfs_ioctl_search_args_v2 __user *uarg;
+ struct btrfs_ioctl_search_args_v2 args;
+ struct inode *inode;
+ int ret;
+ size_t buf_size;
+ const size_t buf_limit = 16 * 1024 * 1024;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ /* copy search header and buffer size */
+ uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
+ if (copy_from_user(&args, uarg, sizeof(args)))
+ return -EFAULT;
+
+ buf_size = args.buf_size;
+
+ if (buf_size < sizeof(struct btrfs_ioctl_search_header))
+ return -EOVERFLOW;
+
+ /* limit result size to 16MB */
+ if (buf_size > buf_limit)
+ buf_size = buf_limit;
+
+ inode = file_inode(file);
+ ret = search_ioctl(inode, &args.key, &buf_size,
+ (char *)(&uarg->buf[0]));
+ if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
+ ret = -EFAULT;
+ else if (ret == -EOVERFLOW &&
+ copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
+ ret = -EFAULT;
+
return ret;
}
@@ -5198,6 +5291,8 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_trans_end(file);
case BTRFS_IOC_TREE_SEARCH:
return btrfs_ioctl_tree_search(file, argp);
+ case BTRFS_IOC_TREE_SEARCH_V2:
+ return btrfs_ioctl_tree_search_v2(file, argp);
case BTRFS_IOC_INO_LOOKUP:
return btrfs_ioctl_ino_lookup(file, argp);
case BTRFS_IOC_INO_PATHS:
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-01 22:23:04 +0000