Rather than always allocating the high-order XATTR_SIZE_MAX buffer which is costly and prone to failure, only allocate what is needed and realloc if necessary. Fixes https://github.com/coreos/bugs/issues/489 --- fs/overlayfs/copy_up.c | 31 ++++++++++++++++++++++--------- 1 file changed, 22 insertions(+), 9 deletions(-) diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 8f66b39..9426e60 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -22,8 +22,8 @@ int ovl_copy_xattr(struct dentry *old, struct dentry *new) { - ssize_t list_size, size; - char *buf, *name, *value; + ssize_t list_size, size, value_size = 0; + char *buf, *name, *value = NULL; int error; if (!old->d_inode->i_op->getxattr || @@ -41,23 +41,36 @@ int ovl_copy_xattr(struct dentry *old, struct dentry *new) if (!buf) return -ENOMEM; - error = -ENOMEM; - value = kmalloc(XATTR_SIZE_MAX, GFP_KERNEL); - if (!value) - goto out; - list_size = vfs_listxattr(old, buf, list_size); if (list_size <= 0) { error = list_size; - goto out_free_value; + goto out; } for (name = buf; name < (buf + list_size); name += strlen(name) + 1) { - size = vfs_getxattr(old, name, value, XATTR_SIZE_MAX); +retry: + size = vfs_getxattr(old, name, value, value_size); + if (size == -ERANGE) { + size = vfs_getxattr(old, name, NULL, 0); + } + if (size <= 0) { error = size; goto out_free_value; } + + if (size > value_size) { + void *new; + new = krealloc(value, size, GFP_KERNEL); + if (!new) { + error = -ENOMEM; + goto out_free_value; + } + value = new; + value_size = size; + goto retry; + } + error = security_inode_copy_up_xattr(old, new, name, value, &size); if (error < 0) -- 2.4.6 -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
