diff options
| author | Junichi Nomura <j-nomura@ce.jp.nec.com> | 2015-10-06 04:32:57 +0000 |
|---|---|---|
| committer | James Bottomley <JBottomley@Odin.com> | 2015-10-27 11:22:37 +0900 |
| commit | 23695e41a1cac017edad2b38607f33678a31b877 (patch) | |
| tree | 2cadb3d6276f29f8a3555b8601d91c4aaa15d50e | |
| parent | 2280521719e81919283b82902ac24058f87dfc1b (diff) | |
| download | linux-23695e41a1cac017edad2b38607f33678a31b877.tar.gz | |
scsi_dh: fix use-after-free when removing scsi device
The commit 1bab0de0274f ("dm-mpath, scsi_dh: don't let dm detach device
handlers") removed reference counting of attached scsi device handler.
As a result, handler data is freed immediately via scsi_dh->detach()
in the context of scsi_remove_device() where activation request can be
still in flight.
This patch moves scsi_dh_handler_detach() to sdev releasing function,
scsi_device_dev_release_usercontext(), at that point the device
is already in quiesced state.
Fixes: 1bab0de0274f ("dm-mpath, scsi_dh: don't let dm detach device handlers")
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
| -rw-r--r-- | drivers/scsi/scsi_dh.c | 6 | ||||
| -rw-r--r-- | drivers/scsi/scsi_priv.h | 2 | ||||
| -rw-r--r-- | drivers/scsi/scsi_sysfs.c | 2 |
3 files changed, 9 insertions, 1 deletions
diff --git a/drivers/scsi/scsi_dh.c b/drivers/scsi/scsi_dh.c index 0a2168e69bbc..cb78388de3fc 100644 --- a/drivers/scsi/scsi_dh.c +++ b/drivers/scsi/scsi_dh.c @@ -232,10 +232,14 @@ int scsi_dh_add_device(struct scsi_device *sdev) return err; } -void scsi_dh_remove_device(struct scsi_device *sdev) +void scsi_dh_release_device(struct scsi_device *sdev) { if (sdev->handler) scsi_dh_handler_detach(sdev); +} + +void scsi_dh_remove_device(struct scsi_device *sdev) +{ device_remove_file(&sdev->sdev_gendev, &scsi_dh_state_attr); } diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index 644bb7339b55..4d01cdb1b348 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -173,9 +173,11 @@ extern struct async_domain scsi_sd_probe_domain; /* scsi_dh.c */ #ifdef CONFIG_SCSI_DH int scsi_dh_add_device(struct scsi_device *sdev); +void scsi_dh_release_device(struct scsi_device *sdev); void scsi_dh_remove_device(struct scsi_device *sdev); #else static inline int scsi_dh_add_device(struct scsi_device *sdev) { return 0; } +static inline void scsi_dh_release_device(struct scsi_device *sdev) { } static inline void scsi_dh_remove_device(struct scsi_device *sdev) { } #endif diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index b333389f248f..dff8fafb741c 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -399,6 +399,8 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work) sdev = container_of(work, struct scsi_device, ew.work); + scsi_dh_release_device(sdev); + parent = sdev->sdev_gendev.parent; spin_lock_irqsave(sdev->host->host_lock, flags); |