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| author | Bart Van Assche <bart.vanassche@sandisk.com> | 2017-05-04 00:31:29 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-05-04 08:23:39 -0600 |
| commit | 18d4d7d0571f5acc9de638ea3a33e8064deaceca (patch) | |
| tree | 928660479764e5f64aa60ea5492dde310de268d7 /block | |
| parent | f57de23ac9019ea84c548a1637d5562ef07a8f7e (diff) | |
| download | lwn-18d4d7d0571f5acc9de638ea3a33e8064deaceca.tar.gz lwn-18d4d7d0571f5acc9de638ea3a33e8064deaceca.zip | |
blk-mq: Do not invoke queue operations on a dead queue
In commit e869b5462f83 ("blk-mq: Unregister debugfs attributes
earlier"), we shuffled the debugfs cleanup around so that the "state"
attribute was removed before we freed the blk-mq data structures.
However, later changes are going to undo that, so we need to explicitly
disallow running a dead queue.
[Omar: rebased and updated commit message]
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq-debugfs.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 1579af6fcbed..347fbb8e059c 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -102,6 +102,14 @@ static ssize_t queue_state_write(void *data, const char __user *buf, struct request_queue *q = data; char opbuf[16] = { }, *op; + /* + * The "state" attribute is removed after blk_cleanup_queue() has called + * blk_mq_free_queue(). Return if QUEUE_FLAG_DEAD has been set to avoid + * triggering a use-after-free. + */ + if (blk_queue_dead(q)) + return -ENOENT; + if (count >= sizeof(opbuf)) { pr_err("%s: operation too long\n", __func__); goto inval; |