Commit 22cc37a9 authored by Lars Ellenberg's avatar Lars Ellenberg Committed by Philipp Reisner
Browse files

drbd: fix unlikely access after free and list corruption 



Various cleanup paths have been incomplete, for the very unlikely case
that we cannot allocate enough bios from process context when submitting
on behalf of the peer or resync process.

Never observed.

Signed-off-by: default avatarPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
parent af85e8e8

drivers/block/drbd/drbd_receiver.c

+25 −0
Original line number Diff line number Diff line
@@ -1573,6 +1573,13 @@ static int recv_resync_read(struct drbd_conf *mdev, sector_t sector, int data_si 
	if (drbd_submit_ee(mdev, e, WRITE, DRBD_FAULT_RS_WR) == 0)

		return TRUE;



	/* drbd_submit_ee currently fails for one reason only:

	 * not being able to allocate enough bios.

	 * Is dropping the connection going to help? */

	spin_lock_irq(&mdev->req_lock);

	list_del(&e->w.list);

	spin_unlock_irq(&mdev->req_lock);



	drbd_free_ee(mdev, e);

fail:

	put_ldev(mdev);
@@ -1998,6 +2005,16 @@ static int receive_Data(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned 
	if (drbd_submit_ee(mdev, e, rw, DRBD_FAULT_DT_WR) == 0)

		return TRUE;



	/* drbd_submit_ee currently fails for one reason only:

	 * not being able to allocate enough bios.

	 * Is dropping the connection going to help? */

	spin_lock_irq(&mdev->req_lock);

	list_del(&e->w.list);

	hlist_del_init(&e->colision);

	spin_unlock_irq(&mdev->req_lock);

	if (e->flags & EE_CALL_AL_COMPLETE_IO)

		drbd_al_complete_io(mdev, e->sector);



out_interrupted:

	/* yes, the epoch_size now is imbalanced.

	 * but we drop the connection anyways, so we don't have a chance to
@@ -2202,6 +2219,14 @@ submit: 
	if (drbd_submit_ee(mdev, e, READ, fault_type) == 0)

		return TRUE;



	/* drbd_submit_ee currently fails for one reason only:

	 * not being able to allocate enough bios.

	 * Is dropping the connection going to help? */

	spin_lock_irq(&mdev->req_lock);

	list_del(&e->w.list);

	spin_unlock_irq(&mdev->req_lock);

	/* no drbd_rs_complete_io(), we are dropping the connection anyways */



out_free_e:

	put_ldev(mdev);

	drbd_free_ee(mdev, e);

drivers/block/drbd/drbd_worker.c

+7 −0
Original line number Diff line number Diff line
@@ -387,6 +387,13 @@ static int read_for_csum(struct drbd_conf *mdev, sector_t sector, int size) 
	if (drbd_submit_ee(mdev, e, READ, DRBD_FAULT_RS_RD) == 0)

		return 0;



	/* drbd_submit_ee currently fails for one reason only:

	 * not being able to allocate enough bios.

	 * Is dropping the connection going to help? */

	spin_lock_irq(&mdev->req_lock);

	list_del(&e->w.list);

	spin_unlock_irq(&mdev->req_lock);



	drbd_free_ee(mdev, e);

defer:

	put_ldev(mdev);

include/linux/drbd.h

+2 −2
Original line number Diff line number Diff line
@@ -53,10 +53,10 @@ 




extern const char *drbd_buildtag(void);

#define REL_VERSION "8.3.8.1"

#define REL_VERSION "8.3.9rc1"

#define API_VERSION 88

#define PRO_VERSION_MIN 86

#define PRO_VERSION_MAX 94

#define PRO_VERSION_MAX 95





enum drbd_io_error_p {

CRA Git | Maintained and supported by SUSTech CRA and CCSE