mirror of
https://github.com/torvalds/linux.git
synced 2024-11-10 14:11:52 +00:00
8b44ca2b63
The checks for maximum metadata block size is missing
SQUASHFS_BLOCK_OFFSET (the two byte length count).
Link: https://lkml.kernel.org/r/2069685113.2081245.1614583677427@webmail.123-reg.co.uk
Fixes: f37aa4c736 ("squashfs: add more sanity checks in id lookup")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Sean Nyekjaer <sean@geanix.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
116 lines
3.0 KiB
C
116 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Squashfs - a compressed read only filesystem for Linux
|
|
*
|
|
* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
|
|
* Phillip Lougher <phillip@squashfs.org.uk>
|
|
*
|
|
* id.c
|
|
*/
|
|
|
|
/*
|
|
* This file implements code to handle uids and gids.
|
|
*
|
|
* For space efficiency regular files store uid and gid indexes, which are
|
|
* converted to 32-bit uids/gids using an id look up table. This table is
|
|
* stored compressed into metadata blocks. A second index table is used to
|
|
* locate these. This second index table for speed of access (and because it
|
|
* is small) is read at mount time and cached in memory.
|
|
*/
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/vfs.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include "squashfs_fs.h"
|
|
#include "squashfs_fs_sb.h"
|
|
#include "squashfs.h"
|
|
|
|
/*
|
|
* Map uid/gid index into real 32-bit uid/gid using the id look up table
|
|
*/
|
|
int squashfs_get_id(struct super_block *sb, unsigned int index,
|
|
unsigned int *id)
|
|
{
|
|
struct squashfs_sb_info *msblk = sb->s_fs_info;
|
|
int block = SQUASHFS_ID_BLOCK(index);
|
|
int offset = SQUASHFS_ID_BLOCK_OFFSET(index);
|
|
u64 start_block;
|
|
__le32 disk_id;
|
|
int err;
|
|
|
|
if (index >= msblk->ids)
|
|
return -EINVAL;
|
|
|
|
start_block = le64_to_cpu(msblk->id_table[block]);
|
|
|
|
err = squashfs_read_metadata(sb, &disk_id, &start_block, &offset,
|
|
sizeof(disk_id));
|
|
if (err < 0)
|
|
return err;
|
|
|
|
*id = le32_to_cpu(disk_id);
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* Read uncompressed id lookup table indexes from disk into memory
|
|
*/
|
|
__le64 *squashfs_read_id_index_table(struct super_block *sb,
|
|
u64 id_table_start, u64 next_table, unsigned short no_ids)
|
|
{
|
|
unsigned int length = SQUASHFS_ID_BLOCK_BYTES(no_ids);
|
|
unsigned int indexes = SQUASHFS_ID_BLOCKS(no_ids);
|
|
int n;
|
|
__le64 *table;
|
|
u64 start, end;
|
|
|
|
TRACE("In read_id_index_table, length %d\n", length);
|
|
|
|
/* Sanity check values */
|
|
|
|
/* there should always be at least one id */
|
|
if (no_ids == 0)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
/*
|
|
* The computed size of the index table (length bytes) should exactly
|
|
* match the table start and end points
|
|
*/
|
|
if (length != (next_table - id_table_start))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
table = squashfs_read_table(sb, id_table_start, length);
|
|
if (IS_ERR(table))
|
|
return table;
|
|
|
|
/*
|
|
* table[0], table[1], ... table[indexes - 1] store the locations
|
|
* of the compressed id blocks. Each entry should be less than
|
|
* the next (i.e. table[0] < table[1]), and the difference between them
|
|
* should be SQUASHFS_METADATA_SIZE or less. table[indexes - 1]
|
|
* should be less than id_table_start, and again the difference
|
|
* should be SQUASHFS_METADATA_SIZE or less
|
|
*/
|
|
for (n = 0; n < (indexes - 1); n++) {
|
|
start = le64_to_cpu(table[n]);
|
|
end = le64_to_cpu(table[n + 1]);
|
|
|
|
if (start >= end || (end - start) >
|
|
(SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) {
|
|
kfree(table);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
}
|
|
|
|
start = le64_to_cpu(table[indexes - 1]);
|
|
if (start >= id_table_start || (id_table_start - start) >
|
|
(SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) {
|
|
kfree(table);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
return table;
|
|
}
|