git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From stable+bounces-198030-greg=kroah.com@vger.kernel.org Tue Dec  2 02:48:56 2025
   2 From: Sasha Levin <sashal@kernel.org>
   3 Date: Mon,  1 Dec 2025 20:48:40 -0500
   4 Subject: usb: uas: fix urb unmapping issue when the uas device is remove during ongoing data transfer
   5 To: stable@vger.kernel.org
   6 Cc: Owen Gu <guhuinan@xiaomi.com>, stable <stable@kernel.org>, Yu Chen <chenyu45@xiaomi.com>, Oliver Neukum <oneukum@suse.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Sasha Levin <sashal@kernel.org>
   7 Message-ID: <20251202014840.1603338-1-sashal@kernel.org>
   8
   9 From: Owen Gu <guhuinan@xiaomi.com>
  10
  11 [ Upstream commit 26d56a9fcb2014b99e654127960aa0a48a391e3c ]
  12
  13 When a UAS device is unplugged during data transfer, there is
  14 a probability of a system panic occurring. The root cause is
  15 an access to an invalid memory address during URB callback handling.
  16 Specifically, this happens when the dma_direct_unmap_sg() function
  17 is called within the usb_hcd_unmap_urb_for_dma() interface, but the
  18 sg->dma_address field is 0 and the sg data structure has already been
  19 freed.
  20
  21 The SCSI driver sends transfer commands by invoking uas_queuecommand_lck()
  22 in uas.c, using the uas_submit_urbs() function to submit requests to USB.
  23 Within the uas_submit_urbs() implementation, three URBs (sense_urb,
  24 data_urb, and cmd_urb) are sequentially submitted. Device removal may
  25 occur at any point during uas_submit_urbs execution, which may result
  26 in URB submission failure. However, some URBs might have been successfully
  27 submitted before the failure, and uas_submit_urbs will return the -ENODEV
  28 error code in this case. The current error handling directly calls
  29 scsi_done(). In the SCSI driver, this eventually triggers scsi_complete()
  30 to invoke scsi_end_request() for releasing the sgtable. The successfully
  31 submitted URBs, when being unlinked to giveback, call
  32 usb_hcd_unmap_urb_for_dma() in hcd.c, leading to exceptions during sg
  33 unmapping operations since the sg data structure has already been freed.
  34
  35 This patch modifies the error condition check in the uas_submit_urbs()
  36 function. When a UAS device is removed but one or more URBs have already
  37 been successfully submitted to USB, it avoids immediately invoking
  38 scsi_done() and save the cmnd to devinfo->cmnd array. If the successfully
  39 submitted URBs is completed before devinfo->resetting being set, then
  40 the scsi_done() function will be called within uas_try_complete() after
  41 all pending URB operations are finalized. Otherwise, the scsi_done()
  42 function will be called within uas_zap_pending(), which is executed after
  43 usb_kill_anchored_urbs().
  44
  45 The error handling only takes effect when uas_queuecommand_lck() calls
  46 uas_submit_urbs() and returns the error value -ENODEV . In this case,
  47 the device is disconnected, and the flow proceeds to uas_disconnect(),
  48 where uas_zap_pending() is invoked to call uas_try_complete().
  49
  50 Fixes: eb2a86ae8c54 ("USB: UAS: fix disconnect by unplugging a hub")
  51 Cc: stable <stable@kernel.org>
  52 Signed-off-by: Yu Chen <chenyu45@xiaomi.com>
  53 Signed-off-by: Owen Gu <guhuinan@xiaomi.com>
  54 Acked-by: Oliver Neukum <oneukum@suse.com>
  55 Link: https://patch.msgid.link/20251120123336.3328-1-guhuinan@xiaomi.com
  56 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  57 [ adapted scsi_done(cmnd) helper to older cmnd->scsi_done(cmnd) callback API ]
  58 Signed-off-by: Sasha Levin <sashal@kernel.org>
  59 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  60 ---
  61  drivers/usb/storage/uas.c |    7 ++++++-
  62  1 file changed, 6 insertions(+), 1 deletion(-)
  63
  64 --- a/drivers/usb/storage/uas.c
  65 +++ b/drivers/usb/storage/uas.c
  66 @@ -705,7 +705,11 @@ static int uas_queuecommand_lck(struct s
  67          * of queueing, no matter how fatal the error
  68          */
  69         if (err == -ENODEV) {
  70 -               set_host_byte(cmnd, DID_ERROR);
  71 +               if (cmdinfo->state & (COMMAND_INFLIGHT | DATA_IN_URB_INFLIGHT |
  72 +                               DATA_OUT_URB_INFLIGHT))
  73 +                       goto out;
  74 +
  75 +               set_host_byte(cmnd, DID_NO_CONNECT);
  76                 cmnd->scsi_done(cmnd);
  77                 goto zombie;
  78         }
  79 @@ -718,6 +722,7 @@ static int uas_queuecommand_lck(struct s
  80                 uas_add_work(cmdinfo);
  81         }
  82
  83 +out:
  84         devinfo->cmnd[idx] = cmnd;
  85  zombie:
  86         spin_unlock_irqrestore(&devinfo->lock, flags);