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usb-storage: fix deadlock when a scsi command timeouts more than once

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With faulty usb-storage devices, read/write can timeout, in that case
the SCSI layer will abort and re-issue the command. USB storage has no
internal timeout, it relies on SCSI layer aborting commands via
.eh_abort_handler() for non those responsive devices.

After two consecutive timeouts of the same command, SCSI layer calls
.eh_device_reset_handler(), without calling .eh_abort_handler() first.

With usb-storage, this causes a deadlock:

  -> .eh_device_reset_handler
    -> device_reset
      -> mutex_lock(&(us->dev_mutex));

mutex already by usb_stor_control_thread(), which is waiting for
command completion:

  -> usb_stor_control_thread (mutex taken here)
    -> usb_stor_invoke_transport
      -> usb_stor_Bulk_transport
        -> usb_stor_bulk_srb
	  -> usb_stor_bulk_transfer_sglist
	    -> usb_sg_wait

Make sure we cancel any pending command in .eh_device_reset_handler()
to avoid this.

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Cc: linux-usb@vger.kernel.org
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/all/ZEllnjMKT8ulZbJh@sakura/
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20230505114759.1189741-1-mbizon@freebox.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Maxime Bizon 2023-05-05 13:47:59 +02:00 committed by Greg Kroah-Hartman
parent 8018018d9c
commit a398d5eac6
1 changed files with 21 additions and 7 deletions
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28
drivers/usb/storage/scsiglue.c
View File

@ -406,22 +406,25 @@ static DEF_SCSI_QCMD(queuecommand)
***********************************************************************/
/* Command timeout and abort */
static int command_abort(struct scsi_cmnd *srb)
static int command_abort_matching(struct us_data *us, struct scsi_cmnd *srb_match)
{
struct us_data *us = host_to_us(srb->device->host);
usb_stor_dbg(us, "%s called\n", __func__);
/*
* us->srb together with the TIMED_OUT, RESETTING, and ABORTING
* bits are protected by the host lock.
*/
scsi_lock(us_to_host(us));
/* Is this command still active? */
if (us->srb != srb) {
/* is there any active pending command to abort ? */
if (!us->srb) {
scsi_unlock(us_to_host(us));
usb_stor_dbg(us, "-- nothing to abort\n");
return SUCCESS;
}
/* Does the command match the passed srb if any ? */
if (srb_match && us->srb != srb_match) {
scsi_unlock(us_to_host(us));
usb_stor_dbg(us, "-- pending command mismatch\n");
return FAILED;
}
@ -444,6 +447,14 @@ static int command_abort(struct scsi_cmnd *srb)
return SUCCESS;
}
static int command_abort(struct scsi_cmnd *srb)
{
struct us_data *us = host_to_us(srb->device->host);
usb_stor_dbg(us, "%s called\n", __func__);
return command_abort_matching(us, srb);
}
/*
* This invokes the transport reset mechanism to reset the state of the
* device
@ -455,6 +466,9 @@ static int device_reset(struct scsi_cmnd *srb)
usb_stor_dbg(us, "%s called\n", __func__);
/* abort any pending command before reset */
command_abort_matching(us, NULL);
/* lock the device pointers and do the reset */
mutex_lock(&(us->dev_mutex));
result = us->transport_reset(us);