erofs-utils: skip all unidentified xattrs from local paths

Just warn out but continue.  Don't over-complicate for now.

Reported-by: Gael Donval <gael.donval@manchester.ac.uk>
Closes: https://lore.kernel.org/r/4abed942399fb29933f0fa85cc55d3d795ae8bcd.camel@manchester.ac.uk
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240618111700.267702-1-hsiangkao@linux.alibaba.com

diff --git a/lib/xattr.c b/lib/xattr.c
index 7b263cd41c8b075e713e0c8df016989f203c1d6d..b0f80e95be5100a9620e2d4b4f0f4c4b125adca3 100644 (file)
--- a/lib/xattr.c
+++ b/lib/xattr.c
@@ -193,14 +193,11 @@ static struct xattr_item *get_xattritem(char *kvbuf, unsigned int len[2])
        }
 
        item = malloc(sizeof(*item));
-       if (!item) {
-               free(kvbuf);
+       if (!item)
                return ERR_PTR(-ENOMEM);
-       }
 
        if (!match_prefix(kvbuf, &item->base_index, &item->prefix_len)) {
                free(item);
-               free(kvbuf);
                return ERR_PTR(-ENODATA);
        }
        DBG_BUGON(len[0] < item->prefix_len);
@@ -232,6 +229,7 @@ static struct xattr_item *parse_one_xattr(const char *path, const char *key,
                                          unsigned int keylen)
 {
        ssize_t ret;
+       struct xattr_item *item;
        unsigned int len[2];
        char *kvbuf;
 
@@ -266,20 +264,32 @@ static struct xattr_item *parse_one_xattr(const char *path, const char *key,
                ret = getxattr(path, key, kvbuf + EROFS_XATTR_KSIZE(len),
                               len[1], 0, XATTR_NOFOLLOW);
 #else
-               free(kvbuf);
-               return ERR_PTR(-EOPNOTSUPP);
+               ret = -EOPNOTSUPP;
+               goto out;
 #endif
                if (ret < 0) {
-                       free(kvbuf);
-                       return ERR_PTR(-errno);
+                       ret = -errno;
+                       goto out;
                }
                if (len[1] != ret) {
-                       erofs_err("size of xattr value got changed just now (%u-> %ld)",
+                       erofs_warn("size of xattr value got changed just now (%u-> %ld)",
                                  len[1], (long)ret);
                        len[1] = ret;
                }
        }
-       return get_xattritem(kvbuf, len);
+
+       item = get_xattritem(kvbuf, len);
+       if (!IS_ERR(item))
+               return item;
+       if (item == ERR_PTR(-ENODATA)) {
+               erofs_warn("skipped unidentified xattr: %s", key);
+               ret = 0;
+       } else {
+               ret = PTR_ERR(item);
+       }
+out:
+       free(kvbuf);
+       return ERR_PTR(ret);
 }
 
 static struct xattr_item *erofs_get_selabel_xattr(const char *srcpath,
@@ -291,6 +301,7 @@ static struct xattr_item *erofs_get_selabel_xattr(const char *srcpath,
                int ret;
                unsigned int len[2];
                char *kvbuf, *fspath;
+               struct xattr_item *item;
 
                if (cfg.mount_point)
                        ret = asprintf(&fspath, "/%s/%s", cfg.mount_point,
@@ -324,7 +335,10 @@ static struct xattr_item *erofs_get_selabel_xattr(const char *srcpath,
                sprintf(kvbuf, "%s", XATTR_NAME_SECURITY_SELINUX);
                memcpy(kvbuf + EROFS_XATTR_KSIZE(len), secontext, len[1]);
                freecon(secontext);
-               return get_xattritem(kvbuf, len);
+               item = get_xattritem(kvbuf, len);
+               if (IS_ERR(item))
+                       free(kvbuf);
+               return item;
        }
 #endif
        return NULL;
@@ -370,18 +384,6 @@ static bool erofs_is_skipped_xattr(const char *key)
        if (cfg.sehnd && !strcmp(key, XATTR_SECURITY_PREFIX "selinux"))
                return true;
 #endif
-
-       /* skip xattrs with unidentified "system." prefix */
-       if (!strncmp(key, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) {
-               if (!strcmp(key, XATTR_NAME_POSIX_ACL_ACCESS) ||
-                   !strcmp(key, XATTR_NAME_POSIX_ACL_DEFAULT)) {
-                       return false;
-               } else {
-                       erofs_warn("skip unidentified xattr: %s", key);
-                       return true;
-               }
-       }
-
        return false;
 }
 
@@ -485,8 +487,10 @@ int erofs_setxattr(struct erofs_inode *inode, char *key,
        memcpy(kvbuf + EROFS_XATTR_KSIZE(len), value, size);
 
        item = get_xattritem(kvbuf, len);
-       if (IS_ERR(item))
+       if (IS_ERR(item)) {
+               free(kvbuf);
                return PTR_ERR(item);
+       }
        DBG_BUGON(!item);
 
        return erofs_xattr_add(&inode->i_xattrs, item);
@@ -548,8 +552,10 @@ static int erofs_droid_xattr_set_caps(struct erofs_inode *inode)
        memcpy(kvbuf + EROFS_XATTR_KSIZE(len), &caps, len[1]);
 
        item = get_xattritem(kvbuf, len);
-       if (IS_ERR(item))
+       if (IS_ERR(item)) {
+               free(kvbuf);
                return PTR_ERR(item);
+       }
        DBG_BUGON(!item);
 
        return erofs_xattr_add(&inode->i_xattrs, item);