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author | Maxime Bizon <mbizon@freebox.fr> | 2023-05-05 13:47:59 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-13 18:53:03 +0900 |
commit | a398d5eac6984316e71474e25b975688f282379b (patch) | |
tree | b2bd10d73c1afa09b3588a789732891c38fdc2e2 /drivers | |
parent | 8018018d9c56473067e5358986ce0ee9ce56949f (diff) | |
download | linux-stable-a398d5eac6984316e71474e25b975688f282379b.tar.gz linux-stable-a398d5eac6984316e71474e25b975688f282379b.tar.bz2 linux-stable-a398d5eac6984316e71474e25b975688f282379b.zip |
usb-storage: fix deadlock when a scsi command timeouts more than once
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>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/usb/storage/scsiglue.c | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c index 8931df5a85fd..c54e9805da53 100644 --- a/drivers/usb/storage/scsiglue.c +++ b/drivers/usb/storage/scsiglue.c @@ -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); |