From nobody Fri Dec 19 20:57:18 2025 Received: from outboundhk.mxmail.xiaomi.com (outboundhk.mxmail.xiaomi.com [207.226.244.123]) by smtp.subspace.kernel.org (Postfix) with ESMTP id EBFC554262; Wed, 15 Oct 2025 15:32:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=207.226.244.123 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760542344; cv=none; b=djZ31ZXdm3e0DYJEDcvUfaVzVhwnn/XhJ3iadU5coMp5Kc1+yjYVXAovBf91/dgHjrbxf7mH9msOJQgMgmiQQzU5vWcoos+JK7YAdZ7wyIS27rG693xrb7AH1x6W4k8wKnTsUtfBM4ZekdTzCpDIpwiDZjQ6bSVupofVaylOJB8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760542344; c=relaxed/simple; bh=J3i3YIKMWDZRvFsBd7CoRuqP8FfDRqCh7TD+GtvM1Tw=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=VPcxb7mMuVF6ZOOyTrl8YxCXrfL7o+XZsbcn8zoXSqFL9XzNXez2FE6DyHVaEdvGLyhf/PX6LJlzGfh4OYYx1Hf34gYlZuJdceIxxIdan9ahSfhTC846P/UqtqhTqudUC77QMG9WmOOv2Jeqg9Ja6Cl9iT24k1+C4CrCDmzRxgw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=xiaomi.com; spf=pass smtp.mailfrom=xiaomi.com; arc=none smtp.client-ip=207.226.244.123 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=xiaomi.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xiaomi.com X-CSE-ConnectionGUID: GjiV+sT8QtucxSoaq8d7bQ== X-CSE-MsgGUID: i0SVS0lTTu2qE0nuwMSogQ== X-IronPort-AV: E=Sophos;i="6.19,231,1754928000"; d="scan'208";a="155387784" From: guhuinan To: Oliver Neukum , Alan Stern , Greg Kroah-Hartman CC: , , , , "Yu Chen" , Owen Gu , Michal Pecio Subject: [PATCH v2] usb: uas: fix urb unmapping issue when the uas device is remove during ongoing data transfer Date: Wed, 15 Oct 2025 23:31:57 +0800 Message-ID: <20251015153157.11870-1-guhuinan@xiaomi.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: bj-mbx11.mioffice.cn (10.237.8.131) To BJ-MBX05.mioffice.cn (10.237.8.125) Content-Type: text/plain; charset="utf-8" From: Owen Gu When a UAS device is unplugged during data transfer, there is a probability of a system panic occurring. The root cause is an access to an invalid memory address during URB callback handling. Specifically, this happens when the dma_direct_unmap_sg() function is called within the usb_hcd_unmap_urb_for_dma() interface, but the sg->dma_address field is 0 and the sg data structure has already been freed. The SCSI driver sends transfer commands by invoking uas_queuecommand_lck() in uas.c, using the uas_submit_urbs() function to submit requests to USB. Within the uas_submit_urbs() implementation, three URBs (sense_urb, data_urb, and cmd_urb) are sequentially submitted. Device removal may occur at any point during uas_submit_urbs execution, which may result in URB submission failure. However, some URBs might have been successfully submitted before the failure, and uas_submit_urbs will return the -ENODEV error code in this case. The current error handling directly calls scsi_done(). In the SCSI driver, this eventually triggers scsi_complete() to invoke scsi_end_request() for releasing the sgtable. The successfully submitted URBs, when being unlinked to giveback, call usb_hcd_unmap_urb_for_dma() in hcd.c, leading to exceptions during sg unmapping operations since the sg data structure has already been freed. This patch modifies the error condition check in the uas_submit_urbs() function. When a UAS device is removed but one or more URBs have already been successfully submitted to USB, it avoids immediately invoking scsi_done() and save the cmnd to devinfo->cmnd array. If the successfully submitted URBs is completed before devinfo->resetting being set, then the scsi_done() function will be called within uas_try_complete() after all pending URB operations are finalized. Otherwise, the scsi_done() function will be called within uas_zap_pending(), which is executed after usb_kill_anchored_urbs(). The uas_zap_pending() iterates over devinfo->cmnd array, invoking uas_try_complete() for each command to finalize their handling. Signed-off-by: Yu Chen Signed-off-by: Owen Gu --- v2: Upon uas_submit_urbs() returning -ENODEV despite successful URB submission, the cmnd is added to the devinfo->cmnd array before exiting uas_queuecommand_lck(). v1: https://lore.kernel.org/linux-usb/20250930045309.21588-1-guhuinan@xiaom= i.com/ --- --- drivers/usb/storage/uas.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c index 4ed0dc19afe0..45b01df364f7 100644 --- a/drivers/usb/storage/uas.c +++ b/drivers/usb/storage/uas.c @@ -698,6 +698,10 @@ static int uas_queuecommand_lck(struct scsi_cmnd *cmnd) * of queueing, no matter how fatal the error */ if (err =3D=3D -ENODEV) { + if (cmdinfo->state & (COMMAND_INFLIGHT | DATA_IN_URB_INFLIGHT | + DATA_OUT_URB_INFLIGHT)) + goto out; + set_host_byte(cmnd, DID_NO_CONNECT); scsi_done(cmnd); goto zombie; @@ -711,6 +715,7 @@ static int uas_queuecommand_lck(struct scsi_cmnd *cmnd) uas_add_work(cmnd); } =20 +out: devinfo->cmnd[idx] =3D cmnd; zombie: spin_unlock_irqrestore(&devinfo->lock, flags); --=20 2.43.0