In 'jbd2_fc_wait_bufs' use 'bh' after put buffer head reference count
which may lead to use-after-free.
So judge buffer if uptodate before put buffer head reference count.
Cc: stable@kernel.org
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220914100812.1414768-3-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
for (i = j_fc_off - 1; i >= j_fc_off - num_blks; i--) {
bh = journal->j_fc_wbuf[i];
wait_on_buffer(bh);
- put_bh(bh);
- journal->j_fc_wbuf[i] = NULL;
/*
* Update j_fc_off so jbd2_fc_release_bufs can release remain
* buffer head.
*/
if (unlikely(!buffer_uptodate(bh))) {
- journal->j_fc_off = i;
+ journal->j_fc_off = i + 1;
return -EIO;
}
+ put_bh(bh);
+ journal->j_fc_wbuf[i] = NULL;
}
return 0;