From: Jan Kara jack@suse.cz
[ Upstream commit 10f04d40a9fa29785206c619f80d8beedb778837 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- fs/quota/quota_tree.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c index 0738972e8d3f0..ecd9887b0d1fe 100644 --- a/fs/quota/quota_tree.c +++ b/fs/quota/quota_tree.c @@ -61,7 +61,7 @@ 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) @@ -70,7 +70,7 @@ 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) @@ -283,7 +283,7 @@ 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); @@ -558,7 +558,7 @@ 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: