diff options
| author | Jan Kara <jack@suse.cz> | 2020-11-02 16:32:10 +0100 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2020-11-03 11:17:00 +0100 |
| commit | 10f04d40a9fa29785206c619f80d8beedb778837 (patch) | |
| tree | 9351d9208e5a95fef22ef849c4903d105fdd19e4 /fs/quota | |
| parent | a219ee41899bcfabd63cd6617256d5be13a7f4b6 (diff) | |
quota: Don't overflow quota file offsets
The on-disk quota format supports quota files with upto 2^32 blocks. Be
careful when computing quota file offsets in the quota files from block
numbers as they can overflow 32-bit types. Since quota files larger than
4GB would require ~26 millions of quota users, this is mostly a
theoretical concern now but better be careful, fuzzers would find the
problem sooner or later anyway...
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/quota')
| -rw-r--r-- | fs/quota/quota_tree.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c index a6f856f341dc..c5562c871c8b 100644 --- a/fs/quota/quota_tree.c +++ b/fs/quota/quota_tree.c @@ -62,7 +62,7 @@ static ssize_t read_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf) memset(buf, 0, info->dqi_usable_bs); return sb->s_op->quota_read(sb, info->dqi_type, buf, - info->dqi_usable_bs, blk << info->dqi_blocksize_bits); + info->dqi_usable_bs, (loff_t)blk << info->dqi_blocksize_bits); } static ssize_t write_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf) @@ -71,7 +71,7 @@ static ssize_t write_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf) ssize_t ret; ret = sb->s_op->quota_write(sb, info->dqi_type, buf, - info->dqi_usable_bs, blk << info->dqi_blocksize_bits); + info->dqi_usable_bs, (loff_t)blk << info->dqi_blocksize_bits); if (ret != info->dqi_usable_bs) { quota_error(sb, "dquota write failed"); if (ret >= 0) @@ -284,7 +284,7 @@ static uint find_free_dqentry(struct qtree_mem_dqinfo *info, blk); goto out_buf; } - dquot->dq_off = (blk << info->dqi_blocksize_bits) + + dquot->dq_off = ((loff_t)blk << info->dqi_blocksize_bits) + sizeof(struct qt_disk_dqdbheader) + i * info->dqi_entry_size; kfree(buf); @@ -559,7 +559,7 @@ static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info, ret = -EIO; goto out_buf; } else { - ret = (blk << info->dqi_blocksize_bits) + sizeof(struct + ret = ((loff_t)blk << info->dqi_blocksize_bits) + sizeof(struct qt_disk_dqdbheader) + i * info->dqi_entry_size; } out_buf: |