Commit 11c514a9 authored by Jan Kara's avatar Jan Kara

quota: Sanity-check quota file headers on load

Perform basic sanity checks of quota headers to avoid kernel crashes on
corrupted quota files.

CC: stable@vger.kernel.org
Reported-by: syzbot+f816042a7ae2225f25ba@syzkaller.appspotmail.com
Reviewed-by: default avatarAndreas Dilger <adilger@dilger.ca>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 10f04d40
......@@ -157,6 +157,25 @@ static int v2_read_file_info(struct super_block *sb, int type)
qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
qinfo->dqi_ops = &v2r1_qtree_ops;
}
ret = -EUCLEAN;
/* Some sanity checks of the read headers... */
if ((loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits >
i_size_read(sb_dqopt(sb)->files[type])) {
quota_error(sb, "Number of blocks too big for quota file size (%llu > %llu).",
(loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits,
i_size_read(sb_dqopt(sb)->files[type]));
goto out;
}
if (qinfo->dqi_free_blk >= qinfo->dqi_blocks) {
quota_error(sb, "Free block number too big (%u >= %u).",
qinfo->dqi_free_blk, qinfo->dqi_blocks);
goto out;
}
if (qinfo->dqi_free_entry >= qinfo->dqi_blocks) {
quota_error(sb, "Block with free entry too big (%u >= %u).",
qinfo->dqi_free_entry, qinfo->dqi_blocks);
goto out;
}
ret = 0;
out:
up_read(&dqopt->dqio_sem);
......
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