diff options
Diffstat (limited to 'fs/ext4/xattr.c')
-rw-r--r-- | fs/ext4/xattr.c | 121 |
1 files changed, 68 insertions, 53 deletions
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 63656dbafdc4..499cb4b1fbd2 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -195,10 +195,13 @@ ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end, /* Check the values */ while (!IS_LAST_ENTRY(entry)) { - if (entry->e_value_size != 0 && - entry->e_value_inum == 0) { + u32 size = le32_to_cpu(entry->e_value_size); + + if (size > EXT4_XATTR_SIZE_MAX) + return -EFSCORRUPTED; + + if (size != 0 && entry->e_value_inum == 0) { u16 offs = le16_to_cpu(entry->e_value_offs); - u32 size = le32_to_cpu(entry->e_value_size); void *value; /* @@ -222,25 +225,36 @@ ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end, } static inline int -ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh) +__ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh, + const char *function, unsigned int line) { - int error; + int error = -EFSCORRUPTED; if (buffer_verified(bh)) return 0; if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || BHDR(bh)->h_blocks != cpu_to_le32(1)) - return -EFSCORRUPTED; + goto errout; + error = -EFSBADCRC; if (!ext4_xattr_block_csum_verify(inode, bh)) - return -EFSBADCRC; + goto errout; error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size, bh->b_data); - if (!error) +errout: + if (error) + __ext4_error_inode(inode, function, line, 0, + "corrupted xattr block %llu", + (unsigned long long) bh->b_blocknr); + else set_buffer_verified(bh); return error; } +#define ext4_xattr_check_block(inode, bh) \ + __ext4_xattr_check_block((inode), (bh), __func__, __LINE__) + + static int __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, void *end, const char *function, unsigned int line) @@ -262,18 +276,22 @@ errout: __xattr_check_inode((inode), (header), (end), __func__, __LINE__) static int -ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index, - const char *name, int sorted) +xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry, + void *end, int name_index, const char *name, int sorted) { - struct ext4_xattr_entry *entry; + struct ext4_xattr_entry *entry, *next; size_t name_len; int cmp = 1; if (name == NULL) return -EINVAL; name_len = strlen(name); - entry = *pentry; - for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { + for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) { + next = EXT4_XATTR_NEXT(entry); + if ((void *) next >= end) { + EXT4_ERROR_INODE(inode, "corrupted xattr entries"); + return -EFSCORRUPTED; + } cmp = name_index - entry->e_name_index; if (!cmp) cmp = name_len - entry->e_name_len; @@ -495,6 +513,7 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, struct buffer_head *bh = NULL; struct ext4_xattr_entry *entry; size_t size; + void *end; int error; struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); @@ -511,20 +530,20 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, goto cleanup; ea_bdebug(bh, "b_count=%d, refcount=%d", atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); - if (ext4_xattr_check_block(inode, bh)) { - EXT4_ERROR_INODE(inode, "bad block %llu", - EXT4_I(inode)->i_file_acl); - error = -EFSCORRUPTED; + error = ext4_xattr_check_block(inode, bh); + if (error) goto cleanup; - } ext4_xattr_block_cache_insert(ea_block_cache, bh); entry = BFIRST(bh); - error = ext4_xattr_find_entry(&entry, name_index, name, 1); + end = bh->b_data + bh->b_size; + error = xattr_find_entry(inode, &entry, end, name_index, name, 1); if (error) goto cleanup; size = le32_to_cpu(entry->e_value_size); + error = -ERANGE; + if (unlikely(size > EXT4_XATTR_SIZE_MAX)) + goto cleanup; if (buffer) { - error = -ERANGE; if (size > buffer_size) goto cleanup; if (entry->e_value_inum) { @@ -533,8 +552,12 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, if (error) goto cleanup; } else { - memcpy(buffer, bh->b_data + - le16_to_cpu(entry->e_value_offs), size); + u16 offset = le16_to_cpu(entry->e_value_offs); + void *p = bh->b_data + offset; + + if (unlikely(p + size > end)) + goto cleanup; + memcpy(buffer, p, size); } } error = size; @@ -568,12 +591,14 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, if (error) goto cleanup; entry = IFIRST(header); - error = ext4_xattr_find_entry(&entry, name_index, name, 0); + error = xattr_find_entry(inode, &entry, end, name_index, name, 0); if (error) goto cleanup; size = le32_to_cpu(entry->e_value_size); + error = -ERANGE; + if (unlikely(size > EXT4_XATTR_SIZE_MAX)) + goto cleanup; if (buffer) { - error = -ERANGE; if (size > buffer_size) goto cleanup; if (entry->e_value_inum) { @@ -582,8 +607,12 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, if (error) goto cleanup; } else { - memcpy(buffer, (void *)IFIRST(header) + - le16_to_cpu(entry->e_value_offs), size); + u16 offset = le16_to_cpu(entry->e_value_offs); + void *p = (void *)IFIRST(header) + offset; + + if (unlikely(p + size > end)) + goto cleanup; + memcpy(buffer, p, size); } } error = size; @@ -676,12 +705,9 @@ ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size) goto cleanup; ea_bdebug(bh, "b_count=%d, refcount=%d", atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); - if (ext4_xattr_check_block(inode, bh)) { - EXT4_ERROR_INODE(inode, "bad block %llu", - EXT4_I(inode)->i_file_acl); - error = -EFSCORRUPTED; + error = ext4_xattr_check_block(inode, bh); + if (error) goto cleanup; - } ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh); error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size); @@ -808,10 +834,9 @@ int ext4_get_inode_usage(struct inode *inode, qsize_t *usage) goto out; } - if (ext4_xattr_check_block(inode, bh)) { - ret = -EFSCORRUPTED; + ret = ext4_xattr_check_block(inode, bh); + if (ret) goto out; - } for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) @@ -1793,19 +1818,16 @@ ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, ea_bdebug(bs->bh, "b_count=%d, refcount=%d", atomic_read(&(bs->bh->b_count)), le32_to_cpu(BHDR(bs->bh)->h_refcount)); - if (ext4_xattr_check_block(inode, bs->bh)) { - EXT4_ERROR_INODE(inode, "bad block %llu", - EXT4_I(inode)->i_file_acl); - error = -EFSCORRUPTED; + error = ext4_xattr_check_block(inode, bs->bh); + if (error) goto cleanup; - } /* Find the named attribute. */ bs->s.base = BHDR(bs->bh); bs->s.first = BFIRST(bs->bh); bs->s.end = bs->bh->b_data + bs->bh->b_size; bs->s.here = bs->s.first; - error = ext4_xattr_find_entry(&bs->s.here, i->name_index, - i->name, 1); + error = xattr_find_entry(inode, &bs->s.here, bs->s.end, + i->name_index, i->name, 1); if (error && error != -ENODATA) goto cleanup; bs->s.not_found = error; @@ -2164,8 +2186,8 @@ int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, if (error) return error; /* Find the named attribute. */ - error = ext4_xattr_find_entry(&is->s.here, i->name_index, - i->name, 0); + error = xattr_find_entry(inode, &is->s.here, is->s.end, + i->name_index, i->name, 0); if (error && error != -ENODATA) return error; is->s.not_found = error; @@ -2721,13 +2743,9 @@ retry: error = -EIO; if (!bh) goto cleanup; - if (ext4_xattr_check_block(inode, bh)) { - EXT4_ERROR_INODE(inode, "bad block %llu", - EXT4_I(inode)->i_file_acl); - error = -EFSCORRUPTED; - brelse(bh); + error = ext4_xattr_check_block(inode, bh); + if (error) goto cleanup; - } base = BHDR(bh); end = bh->b_data + bh->b_size; min_offs = end - base; @@ -2884,11 +2902,8 @@ int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode, goto cleanup; } error = ext4_xattr_check_block(inode, bh); - if (error) { - EXT4_ERROR_INODE(inode, "bad block %llu (error %d)", - EXT4_I(inode)->i_file_acl, error); + if (error) goto cleanup; - } if (ext4_has_feature_ea_inode(inode->i_sb)) { for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); |