From: Maxime Bizon mbizon@freebox.fr
commit a398d5eac6984316e71474e25b975688f282379b upstream.
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 --- drivers/usb/storage/scsiglue.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-)
--- a/drivers/usb/storage/scsiglue.c +++ b/drivers/usb/storage/scsiglue.c @@ -408,22 +408,25 @@ 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; }
@@ -446,6 +449,14 @@ static int command_abort(struct scsi_cmn 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 @@ -457,6 +468,9 @@ static int device_reset(struct scsi_cmnd
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);