[PATCH 2/6] sd: improve TUR handling in sd_check_events
From: Christoph Hellwig <hch@lst.de>
Date: 2017-02-14 19:16:11
Also in:
linux-scsi
Subsystem:
scsi subsystem, the rest · Maintainers:
"James E.J. Bottomley", "Martin K. Petersen", Linus Torvalds
Remove bogus evaluations of retval and sshdr when the device is offline, and fix a possible NULL pointer dereference by allocating the 8 byte sized sense header on stack. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/scsi/sd.c | 25 +++++++++++-------------- 1 file changed, 11 insertions(+), 14 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 40b4038c019e..11e290d1dbff 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c@@ -1425,7 +1425,6 @@ static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing) { struct scsi_disk *sdkp = scsi_disk_get(disk); struct scsi_device *sdp; - struct scsi_sense_hdr *sshdr = NULL; int retval; if (!sdkp)
@@ -1454,22 +1453,21 @@ static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing) * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever * sd_revalidate() is called. */ - retval = -ENODEV; - if (scsi_block_when_processing_errors(sdp)) { - sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); + struct scsi_sense_hdr sshdr = { 0, }; + retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES, - sshdr); - } + &sshdr); - /* failed to execute TUR, assume media not present */ - if (host_byte(retval)) { - set_media_not_present(sdkp); - goto out; - } + /* failed to execute TUR, assume media not present */ + if (host_byte(retval)) { + set_media_not_present(sdkp); + goto out; + } - if (media_not_present(sdkp, sshdr)) - goto out; + if (media_not_present(sdkp, &sshdr)) + goto out; + } /* * For removable scsi disk we have to recognise the presence
@@ -1485,7 +1483,6 @@ static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing) * Medium present state has changed in either direction. * Device has indicated UNIT_ATTENTION. */ - kfree(sshdr); retval = sdp->changed ? DISK_EVENT_MEDIA_CHANGE : 0; sdp->changed = 0; scsi_disk_put(sdkp);
--
2.11.0