mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-25 11:55:37 +00:00
dm crypt: avoid accessing uninitialized tasklet
commitd9a02e016a
upstream. When neither "no_read_workqueue" nor "no_write_workqueue" are enabled, tasklet_trylock() in crypt_dec_pending() may still return false due to an uninitialized state, and dm-crypt will unnecessarily do io completion in io_queue workqueue instead of current context. Fix this by adding an 'in_tasklet' flag to dm_crypt_io struct and initialize it to false in crypt_io_init(). Set this flag to true in kcryptd_queue_crypt() before calling tasklet_schedule(). If set crypt_dec_pending() will punt io completion to a workqueue. This also nicely avoids the tasklet_trylock/unlock hack when tasklets aren't in use. Fixes:8e14f61015
("dm crypt: do not call bio_endio() from the dm-crypt tasklet") Cc: stable@vger.kernel.org Reported-by: Hou Tao <houtao1@huawei.com> Suggested-by: Ignat Korchagin <ignat@cloudflare.com> Reviewed-by: Ignat Korchagin <ignat@cloudflare.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
eb485b7404
commit
1ac20290f6
1 changed files with 9 additions and 6 deletions
|
@ -68,7 +68,9 @@ struct dm_crypt_io {
|
||||||
struct crypt_config *cc;
|
struct crypt_config *cc;
|
||||||
struct bio *base_bio;
|
struct bio *base_bio;
|
||||||
u8 *integrity_metadata;
|
u8 *integrity_metadata;
|
||||||
bool integrity_metadata_from_pool;
|
bool integrity_metadata_from_pool:1;
|
||||||
|
bool in_tasklet:1;
|
||||||
|
|
||||||
struct work_struct work;
|
struct work_struct work;
|
||||||
struct tasklet_struct tasklet;
|
struct tasklet_struct tasklet;
|
||||||
|
|
||||||
|
@ -1723,6 +1725,7 @@ static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
|
||||||
io->ctx.r.req = NULL;
|
io->ctx.r.req = NULL;
|
||||||
io->integrity_metadata = NULL;
|
io->integrity_metadata = NULL;
|
||||||
io->integrity_metadata_from_pool = false;
|
io->integrity_metadata_from_pool = false;
|
||||||
|
io->in_tasklet = false;
|
||||||
atomic_set(&io->io_pending, 0);
|
atomic_set(&io->io_pending, 0);
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -1768,14 +1771,13 @@ static void crypt_dec_pending(struct dm_crypt_io *io)
|
||||||
* our tasklet. In this case we need to delay bio_endio()
|
* our tasklet. In this case we need to delay bio_endio()
|
||||||
* execution to after the tasklet is done and dequeued.
|
* execution to after the tasklet is done and dequeued.
|
||||||
*/
|
*/
|
||||||
if (tasklet_trylock(&io->tasklet)) {
|
if (io->in_tasklet) {
|
||||||
tasklet_unlock(&io->tasklet);
|
INIT_WORK(&io->work, kcryptd_io_bio_endio);
|
||||||
bio_endio(base_bio);
|
queue_work(cc->io_queue, &io->work);
|
||||||
return;
|
return;
|
||||||
}
|
}
|
||||||
|
|
||||||
INIT_WORK(&io->work, kcryptd_io_bio_endio);
|
bio_endio(base_bio);
|
||||||
queue_work(cc->io_queue, &io->work);
|
|
||||||
}
|
}
|
||||||
|
|
||||||
/*
|
/*
|
||||||
|
@ -2229,6 +2231,7 @@ static void kcryptd_queue_crypt(struct dm_crypt_io *io)
|
||||||
* it is being executed with irqs disabled.
|
* it is being executed with irqs disabled.
|
||||||
*/
|
*/
|
||||||
if (in_hardirq() || irqs_disabled()) {
|
if (in_hardirq() || irqs_disabled()) {
|
||||||
|
io->in_tasklet = true;
|
||||||
tasklet_init(&io->tasklet, kcryptd_crypt_tasklet, (unsigned long)&io->work);
|
tasklet_init(&io->tasklet, kcryptd_crypt_tasklet, (unsigned long)&io->work);
|
||||||
tasklet_schedule(&io->tasklet);
|
tasklet_schedule(&io->tasklet);
|
||||||
return;
|
return;
|
||||||
|
|
Loading…
Reference in a new issue