fs: ext4: fix crash on ext4ls

[oweals/u-boot.git] / fs / ext4 / ext4fs.c

diff --git a/fs/ext4/ext4fs.c b/fs/ext4/ext4fs.c
index 943b5bcf35e903382dbc7f928d6577b6874c51c4..2a28031d14ca1f23a43dc72ac53e8f1e2b731cde 100644 (file)
--- a/fs/ext4/ext4fs.c
+++ b/fs/ext4/ext4fs.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * (C) Copyright 2011 - 2012 Samsung Electronics
  * EXT4 filesystem implementation in Uboot by
@@ -17,14 +18,13 @@
  * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
  *
  * ext4write : Based on generic ext4 protocol.
- *
- * SPDX-License-Identifier:    GPL-2.0+
  */
 
 #include <common.h>
 #include <ext_common.h>
 #include <ext4fs.h>
 #include "ext4_common.h"
+#include <div64.h>
 
 int ext4fs_symlinknest;
 struct ext_filesystem ext_fs;
@@ -54,7 +54,7 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
        int log2blksz = fs->dev_desc->log2blksz;
        int log2_fs_blocksize = LOG2_BLOCK_SIZE(node->data) - log2blksz;
        int blocksize = (1 << (log2_fs_blocksize + log2blksz));
-       unsigned int filesize = __le32_to_cpu(node->inode.size);
+       unsigned int filesize = le32_to_cpu(node->inode.size);
        lbaint_t previous_block_number = -1;
        lbaint_t delayed_start = 0;
        lbaint_t delayed_extent = 0;
@@ -63,15 +63,18 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
        char *delayed_buf = NULL;
        short status;
 
+       if (blocksize <= 0)
+               return -1;
+
        /* Adjust len so it we can't read past the end of the file. */
-       if (len > filesize)
-               len = filesize;
+       if (len + pos > filesize)
+               len = (filesize - pos);
 
-       blockcnt = ((len + pos) + blocksize - 1) / blocksize;
+       blockcnt = lldiv(((len + pos) + blocksize - 1), blocksize);
 
-       for (i = pos / blocksize; i < blockcnt; i++) {
-               lbaint_t blknr;
-               int blockoff = pos % blocksize;
+       for (i = lldiv(pos, blocksize); i < blockcnt; i++) {
+               long int blknr;
+               int blockoff = pos - (blocksize * i);
                int blockend = blocksize;
                int skipfirst = 0;
                blknr = read_allocated_block(&(node->inode), i);
@@ -82,7 +85,7 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
 
                /* Last block.  */
                if (i == blockcnt - 1) {
-                       blockend = (len + pos) % blocksize;
+                       blockend = (len + pos) - (blocksize * i);
 
                        /* The last portion is exactly blocksize. */
                        if (!blockend)
@@ -90,7 +93,7 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
                }
 
                /* First block. */
-               if (i == pos / blocksize) {
+               if (i == lldiv(pos, blocksize)) {
                        skipfirst = blockoff;
                        blockend -= skipfirst;
                }
@@ -126,6 +129,7 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
                                        (blockend >> log2blksz);
                        }
                } else {
+                       int n;
                        if (previous_block_number != -1) {
                                /* spill */
                                status = ext4fs_devread(delayed_start,
@@ -136,7 +140,11 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
                                        return -1;
                                previous_block_number = -1;
                        }
-                       memset(buf, 0, blocksize - skipfirst);
+                       /* Zero no more than `len' bytes. */
+                       n = blocksize - skipfirst;
+                       if (n > len)
+                               n = len;
+                       memset(buf, 0, n);
                }
                buf += blocksize - skipfirst;
        }
@@ -156,7 +164,7 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
 
 int ext4fs_ls(const char *dirname)
 {
-       struct ext2fs_node *dirnode;
+       struct ext2fs_node *dirnode = NULL;
        int status;
 
        if (dirname == NULL)
@@ -166,6 +174,8 @@ int ext4fs_ls(const char *dirname)
                                  FILETYPE_DIRECTORY);
        if (status != 1) {
                printf("** Can not find directory. **\n");
+               if (dirnode)
+                       ext4fs_free_node(dirnode, &ext4fs_root->diropen);
                return 1;
        }
 
@@ -189,15 +199,15 @@ int ext4fs_size(const char *filename, loff_t *size)
        return ext4fs_open(filename, size);
 }
 
-int ext4fs_read(char *buf, loff_t len, loff_t *actread)
+int ext4fs_read(char *buf, loff_t offset, loff_t len, loff_t *actread)
 {
        if (ext4fs_root == NULL || ext4fs_file == NULL)
-               return 0;
+               return -1;
 
-       return ext4fs_read_file(ext4fs_file, 0, len, buf, actread);
+       return ext4fs_read_file(ext4fs_file, offset, len, buf, actread);
 }
 
-int ext4fs_probe(block_dev_desc_t *fs_dev_desc,
+int ext4fs_probe(struct blk_desc *fs_dev_desc,
                 disk_partition_t *fs_partition)
 {
        ext4fs_set_blk_dev(fs_dev_desc, fs_partition);
@@ -216,11 +226,6 @@ int ext4_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
        loff_t file_len;
        int ret;
 
-       if (offset != 0) {
-               printf("** Cannot support non-zero offset **\n");
-               return -1;
-       }
-
        ret = ext4fs_open(filename, &file_len);
        if (ret < 0) {
                printf("** File not found %s **\n", filename);
@@ -230,7 +235,7 @@ int ext4_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
        if (len == 0)
                len = file_len;
 
-       return ext4fs_read(buf, len, len_read);
+       return ext4fs_read(buf, offset, len, len_read);
 }
 
 int ext4fs_uuid(char *uuid_str)