From nobody Thu Oct 2 00:58:11 2025 Received: from outboundhk.mxmail.xiaomi.com (outboundhk.mxmail.xiaomi.com [207.226.244.123]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 23E0E288DB; Tue, 30 Sep 2025 04:54:31 +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=1759208075; cv=none; b=nA26UK3oinpWcuFTQ/za0xbnZFfGQubraRE9ZYl8RCS0/MdK5fikR9izmGywU1wdUSJp/VQBOrUNk4aAqTE/EfJILNqMrU+8ZnTuc2FJzGJuFtPQN4XHlPazIrAAmtf5L3PuQ0Kc6K/NCLUr3NJOkMQOcEEgwv1YnqRMQHHHYaU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759208075; c=relaxed/simple; bh=Gw5ZjzJnceznZ0FnaMXKyoToW5xxSQMuBie2EAuTFMU=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=jtux+TTPfUZ2v/TVWdb6LZj9iYW/CyHOGsistntMcIsrB178os4KSAX9GbSUy7eot94VhrpJIEpbY68j8j1Eh8AdpreGdEDQOaS3lp0m12sOn2eGbkPQ1XwkPTlIX36G2gr7RZPY9j5Oo7qktxV+pKuRYXXhkTKJToPabT0q4E8= 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: EVtpDxrPSqqcFC7xE6im6Q== X-CSE-MsgGUID: SnU+0+RdRwuxkDHoijzSaQ== X-IronPort-AV: E=Sophos;i="6.18,303,1751212800"; d="scan'208";a="154003711" From: guhuinan To: Oliver Neukum , Alan Stern , Greg Kroah-Hartman CC: , , , , "Yu Chen" , Owen Gu Subject: [PATCH] fix urb unmapping issue when the uas device is remove during ongoing data transfer Date: Tue, 30 Sep 2025 12:53:08 +0800 Message-ID: <20250930045309.21588-1-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 completed (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(). Instead, it waits for the successfully submitted URBs to complete , and then triggers the scsi_done() function call within uas_try_complete() after all pending URB operations are finalized. Signed-off-by: Yu Chen Signed-off-by: Owen Gu --- drivers/usb/storage/uas.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c index 4ed0dc19afe0..6bfc7281f7ad 100644 --- a/drivers/usb/storage/uas.c +++ b/drivers/usb/storage/uas.c @@ -699,7 +699,9 @@ static int uas_queuecommand_lck(struct scsi_cmnd *cmnd) */ if (err =3D=3D -ENODEV) { set_host_byte(cmnd, DID_NO_CONNECT); - scsi_done(cmnd); + if (!(cmdinfo->state & (COMMAND_INFLIGHT | DATA_IN_URB_INFLIGHT | + DATA_OUT_URB_INFLIGHT))) + scsi_done(cmnd); goto zombie; } if (err) { --=20 2.43.0