diff options
Diffstat (limited to 'fs/ext4/xattr.c')
| -rw-r--r-- | fs/ext4/xattr.c | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 59c9ec7eabae..5a94fa52b74f 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -185,6 +185,7 @@ ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end, { struct ext4_xattr_entry *e = entry; + /* Find the end of the names list */ while (!IS_LAST_ENTRY(e)) { struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e); if ((void *)next >= end) @@ -192,15 +193,29 @@ ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end, e = next; } + /* Check the values */ while (!IS_LAST_ENTRY(entry)) { if (entry->e_value_block != 0) return -EFSCORRUPTED; - if (entry->e_value_size != 0 && - (value_start + le16_to_cpu(entry->e_value_offs) < - (void *)e + sizeof(__u32) || - value_start + le16_to_cpu(entry->e_value_offs) + - le32_to_cpu(entry->e_value_size) > end)) - return -EFSCORRUPTED; + if (entry->e_value_size != 0) { + u16 offs = le16_to_cpu(entry->e_value_offs); + u32 size = le32_to_cpu(entry->e_value_size); + void *value; + + /* + * The value cannot overlap the names, and the value + * with padding cannot extend beyond 'end'. Check both + * the padded and unpadded sizes, since the size may + * overflow to 0 when adding padding. + */ + if (offs > end - value_start) + return -EFSCORRUPTED; + value = value_start + offs; + if (value < (void *)e + sizeof(u32) || + size > end - value || + EXT4_XATTR_SIZE(size) > end - value) + return -EFSCORRUPTED; + } entry = EXT4_XATTR_NEXT(entry); } |