f2fs: fix listxattr handling of corrupted xattr entries

Validate the xattr entry before reading its fields in f2fs_listxattr().
Return -EFSCORRUPTED when the entry is outside the valid xattr storage
area instead of returning a successful partial result.

Fixes: 688078e7f36c ("f2fs: fix to avoid memory leakage in f2fs_listxattr")
Cc: stable@kernel.org
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Keshav Verma <iganschel@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index 24cef7e1f56a560eaa69130e2e0030d3bde6b7fb..ed33e5110f2ab1a0164abff045213765b3a517fb 100644 (file)
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -583,8 +583,6 @@ ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
                size_t prefix_len;
                size_t size;
 
-               prefix = f2fs_xattr_prefix(entry->e_name_index, dentry);
-
                if ((void *)(entry) + sizeof(__u32) > last_base_addr ||
                        (void *)XATTR_NEXT_ENTRY(entry) > last_base_addr) {
                        f2fs_err(F2FS_I_SB(inode), "list inode (%llu) has corrupted xattr",
@@ -594,9 +592,11 @@ ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
                                                ERROR_CORRUPTED_XATTR);
                        fserror_report_file_metadata(inode,
                                                -EFSCORRUPTED, GFP_NOFS);
-                       break;
+                       error = -EFSCORRUPTED;
+                       goto cleanup;
                }
 
+               prefix = f2fs_xattr_prefix(entry->e_name_index, dentry);
                if (!prefix)
                        continue;