diff options
| -rw-r--r-- | fs/squashfs/id.c | 30 | ||||
| -rw-r--r-- | fs/squashfs/squashfs.h | 2 | ||||
| -rw-r--r-- | fs/squashfs/super.c | 10 | ||||
| -rw-r--r-- | fs/squashfs/xattr.h | 1 |
4 files changed, 37 insertions, 6 deletions
diff --git a/fs/squashfs/id.c b/fs/squashfs/id.c index 2fdac67..499d08a 100644 --- a/fs/squashfs/id.c +++ b/fs/squashfs/id.c @@ -66,11 +66,37 @@ int squashfs_get_id(struct super_block *sb, unsigned int index, * Read uncompressed id lookup table indexes from disk into memory */ __le64 *squashfs_read_id_index_table(struct super_block *sb, - u64 id_table_start, unsigned short no_ids) + u64 id_table_start, u64 next_table, unsigned short no_ids) { unsigned int length = SQUASHFS_ID_BLOCK_BYTES(no_ids); + __le64 *table; TRACE("In read_id_index_table, length %d\n", length); - return squashfs_read_table(sb, id_table_start, length); + /* Sanity check values */ + + /* there should always be at least one id */ + if (no_ids == 0) + return ERR_PTR(-EINVAL); + + /* + * length bytes should not extend into the next table - this check + * also traps instances where id_table_start is incorrectly larger + * than the next table start + */ + if (id_table_start + length > next_table) + return ERR_PTR(-EINVAL); + + table = squashfs_read_table(sb, id_table_start, length); + + /* + * table[0] points to the first id lookup table metadata block, this + * should be less than id_table_start + */ + if (!IS_ERR(table) && table[0] >= id_table_start) { + kfree(table); + return ERR_PTR(-EINVAL); + } + + return table; } diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h index d622e84..0e3d220 100644 --- a/fs/squashfs/squashfs.h +++ b/fs/squashfs/squashfs.h @@ -61,7 +61,7 @@ extern __le64 *squashfs_read_fragment_index_table(struct super_block *, /* id.c */ extern int squashfs_get_id(struct super_block *, unsigned int, unsigned int *); -extern __le64 *squashfs_read_id_index_table(struct super_block *, u64, +extern __le64 *squashfs_read_id_index_table(struct super_block *, u64, u64, unsigned short); /* inode.c */ diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c index 401cc8c..8f5f278 100644 --- a/fs/squashfs/super.c +++ b/fs/squashfs/super.c @@ -83,7 +83,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent) long long root_inode; unsigned short flags; unsigned int fragments; - u64 lookup_table_start, xattr_id_table_start; + u64 lookup_table_start, xattr_id_table_start, next_table; int err; TRACE("Entered squashfs_fill_superblock\n"); @@ -217,8 +217,10 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent) /* Handle xattrs */ sb->s_xattr = squashfs_xattr_handlers; xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start); - if (xattr_id_table_start == SQUASHFS_INVALID_BLK) + if (xattr_id_table_start == SQUASHFS_INVALID_BLK) { + next_table = msblk->bytes_used; goto allocate_id_index_table; + } /* Allocate and read xattr id lookup table */ msblk->xattr_id_table = squashfs_read_xattr_id_table(sb, @@ -230,11 +232,13 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent) if (err != -ENOTSUPP) goto failed_mount; } + next_table = msblk->xattr_table; allocate_id_index_table: /* Allocate and read id index table */ msblk->id_table = squashfs_read_id_index_table(sb, - le64_to_cpu(sblk->id_table_start), le16_to_cpu(sblk->no_ids)); + le64_to_cpu(sblk->id_table_start), next_table, + le16_to_cpu(sblk->no_ids)); if (IS_ERR(msblk->id_table)) { ERROR("unable to read id index table\n"); err = PTR_ERR(msblk->id_table); diff --git a/fs/squashfs/xattr.h b/fs/squashfs/xattr.h index b634efc..9b3dd6c 100644 --- a/fs/squashfs/xattr.h +++ b/fs/squashfs/xattr.h @@ -31,6 +31,7 @@ static inline __le64 *squashfs_read_xattr_id_table(struct super_block *sb, u64 start, u64 *xattr_table_start, int *xattr_ids) { ERROR("Xattrs in filesystem, these will be ignored\n"); + *xattr_table_start = start; return ERR_PTR(-ENOTSUPP); } |
