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author | Finn Thain <fthain@telegraphics.com.au> | 2016-02-23 10:07:09 +1100 |
---|---|---|
committer | Martin K. Petersen <martin.petersen@oracle.com> | 2016-03-01 09:38:58 -0500 |
commit | 8d5dbec3bcb24a7d071962448e0fecaca8c75cc7 (patch) | |
tree | ccb8868cb74c02bb283bf69d84722dcfe83e1e8c /drivers/scsi/NCR5380.c | |
parent | ccf6efd78317ef6265829c81a3e1a19f628b1a2d (diff) | |
download | linux-8d5dbec3bcb24a7d071962448e0fecaca8c75cc7.tar.gz linux-8d5dbec3bcb24a7d071962448e0fecaca8c75cc7.tar.bz2 linux-8d5dbec3bcb24a7d071962448e0fecaca8c75cc7.zip |
ncr5380: Call scsi_eh_prep_cmnd() and scsi_eh_restore_cmnd() as and when appropriate
This bug causes the wrong command to have its sense pointer overwritten,
which sometimes leads to a NULL pointer deref. Fix this by checking which
command is being requeued before restoring the scsi_eh_save data.
It turns out that some targets will disconnect a REQUEST SENSE command.
The autosense algorithm doesn't anticipate this. Hence multiple commands
can end up undergoing autosense simultaneously, and they will all try to
use the same scsi_eh_save struct, which won't work. Defer autosense when
the scsi_eh_save storage is in use by another command.
Fixes: f27db8eb98a1 ("ncr5380: Fix autosense bugs")
Reported-and-tested-by: Michael Schmitz <schmitzmic@gmail.com>
Cc: <stable@vger.kernel.org> # 4.5
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/NCR5380.c')
-rw-r--r-- | drivers/scsi/NCR5380.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c index e8e579ad3d54..3eff2a69fe08 100644 --- a/drivers/scsi/NCR5380.c +++ b/drivers/scsi/NCR5380.c @@ -760,7 +760,7 @@ static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance) struct NCR5380_cmd *ncmd; struct scsi_cmnd *cmd; - if (list_empty(&hostdata->autosense)) { + if (hostdata->sensing || list_empty(&hostdata->autosense)) { list_for_each_entry(ncmd, &hostdata->unissued, list) { cmd = NCR5380_to_scmd(ncmd); dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n", @@ -793,7 +793,7 @@ static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd) struct NCR5380_hostdata *hostdata = shost_priv(instance); struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd); - if (hostdata->sensing) { + if (hostdata->sensing == cmd) { scsi_eh_restore_cmnd(cmd, &hostdata->ses); list_add(&ncmd->list, &hostdata->autosense); hostdata->sensing = NULL; |