diff options
| -rw-r--r-- | fs/squashfs/export.c | 29 | ||||
| -rw-r--r-- | fs/squashfs/squashfs.h | 2 | ||||
| -rw-r--r-- | fs/squashfs/super.c | 3 |
3 files changed, 30 insertions, 4 deletions
diff --git a/fs/squashfs/export.c b/fs/squashfs/export.c index cc6dd90cee6a..e3108711a40a 100644 --- a/fs/squashfs/export.c +++ b/fs/squashfs/export.c @@ -121,13 +121,38 @@ static struct dentry *squashfs_get_parent(struct dentry *child) * Read uncompressed inode lookup table indexes off disk into memory */ __le64 *squashfs_read_inode_lookup_table(struct super_block *sb, - u64 lookup_table_start, unsigned int inodes) + u64 lookup_table_start, u64 next_table, unsigned int inodes) { unsigned int length = SQUASHFS_LOOKUP_BLOCK_BYTES(inodes); + __le64 *table; TRACE("In read_inode_lookup_table, length %d\n", length); - return squashfs_read_table(sb, lookup_table_start, length); + /* Sanity check values */ + + /* there should always be at least one inode */ + if (inodes == 0) + return ERR_PTR(-EINVAL); + + /* length bytes should not extend into the next table - this check + * also traps instances where lookup_table_start is incorrectly larger + * than the next table start + */ + if (lookup_table_start + length > next_table) + return ERR_PTR(-EINVAL); + + table = squashfs_read_table(sb, lookup_table_start, length); + + /* + * table[0] points to the first inode lookup table metadata block, + * this should be less than lookup_table_start + */ + if (!IS_ERR(table) && table[0] >= lookup_table_start) { + kfree(table); + return ERR_PTR(-EINVAL); + } + + return table; } diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h index 0e3d220defd2..3b705f137ebb 100644 --- a/fs/squashfs/squashfs.h +++ b/fs/squashfs/squashfs.h @@ -51,7 +51,7 @@ extern const struct squashfs_decompressor *squashfs_lookup_decompressor(int); extern void *squashfs_decompressor_init(struct super_block *, unsigned short); /* export.c */ -extern __le64 *squashfs_read_inode_lookup_table(struct super_block *, u64, +extern __le64 *squashfs_read_inode_lookup_table(struct super_block *, u64, u64, unsigned int); /* fragment.c */ diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c index 8f5f2781a60e..80a7119870a6 100644 --- a/fs/squashfs/super.c +++ b/fs/squashfs/super.c @@ -245,6 +245,7 @@ allocate_id_index_table: msblk->id_table = NULL; goto failed_mount; } + next_table = msblk->id_table[0]; /* Handle inode lookup table */ lookup_table_start = le64_to_cpu(sblk->lookup_table_start); @@ -253,7 +254,7 @@ allocate_id_index_table: /* Allocate and read inode lookup table */ msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb, - lookup_table_start, msblk->inodes); + lookup_table_start, next_table, msblk->inodes); if (IS_ERR(msblk->inode_lookup_table)) { ERROR("unable to read inode lookup table\n"); err = PTR_ERR(msblk->inode_lookup_table); |