From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-100.mta1.migadu.com [95.215.58.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DA3D578F2B for ; Mon, 21 Sep 2026 14:47:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.100 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790002066; cv=none; b=pjlIw0dSjDjOU8mhvldlmY+JM3rfAacxcAKzc4P8zNj95EO5EQnYqmangf61oyALZQW/3levBsMZKkaaZDOYIZqKtuGEXLgtBnrlrc9T0Pv2N6ERHI7F+VfRqWo6TEprdyDVeeIE586CyG+wlLRgYQsFO/iztlTy8zaXE8zFfhE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790002066; c=relaxed/simple; bh=e9WM4rzZg05MFYQKfKbZiGk/o3dn3vwUGCuQuS6yn6c=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=TBaZNQKpvmckmD73mVi6NS6rpOYwD2AOjONY9FyBO+4fbCZC/paF7kevCVMOvi0DYNEpRRbe3S07/z2PF9plLtjMaNNcFNsBlqUIcHE8fGqzkn43ILJoMoHn7NtDXPkntPQQoh9h8tEiIBJ7dfVe/A04vOWDsL4fa6rN0/8wzeM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=g56wJwGp; arc=none smtp.client-ip=95.215.58.100 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="g56wJwGp" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=e9WM4rzZg05MFYQKfKbZiGk/o3dn3vwUGCuQuS6yn6c=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790002061; v=1; x=1790606861; b=g56wJwGp/T1WlLguxfoRDnrKUg+iZuiHvmBdXXXReMpBxZnWhTZxD+5QCPDiRav+CyAOEkSt CmA4rMaDi7MUhpyq6VsxZluqCsGBNT5VgSrd1sSHiLjT6ZRxPOI0lhMu9KB+YCsND1bFbPvq1Gs Yk1VHLvZzvU5TJqxhGDtsrS8= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta12.migadu.com with ESMTPS id 87632ad2fc37c4e0; Mon, 21 Sep 2026 14:47:41 +0000 X-Mizu-Trace-ID: 87632ad2fc37c4e0 X-Migadu-Flow: FLOW_OUT Message-ID: <69218179-d750-4880-8be0-2ccab7d76a6d@linux.dev> Date: Mon, 21 Sep 2026 15:47:41 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] scsi: sg: clean up request on error paths in sg_read() To: Hui Peng , Doug Gilbert , "James E . J . Bottomley" , "Martin K . Petersen" Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260919204814.2815374-1-benquike@gmail.com> Content-Language: en-US From: John Garry In-Reply-To: <20260919204814.2815374-1-benquike@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 9/19/26 21:48, Hui Peng wrote: > In sg_read(), once sg_get_rq_mark() locates a completed Sg_request and > transitions srp->done from 1 to 2, an allocation failure in kzalloc() or > a user-copy fault (-EFAULT) in copy_to_user() / sg_read_oxfer() returns > or jumps to free_old_hdr without calling sg_finish_rem_req(srp) and > sg_remove_request(sfp, srp). > > Because srp->done is already 2, subsequent sg_read() calls skip the > request, permanently leaking srp->bio and keeping sfp->res_in_use = 1 > (blocking SG_SET_RESERVED_SIZE with -EBUSY and wedging non-SG_FLAG_NO_DXFER > writes with -EDOM) until the file descriptor is closed. > > Always call sg_finish_rem_req(srp) and sg_remove_request(sfp, srp) under > the free_old_hdr cleanup label, matching sg_new_read(). > > Fixes: cb59e8408381 ("[PATCH] sg.c: update") > Assisted-by: LLM > Signed-off-by: Hui Peng How was this tested? > --- > diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c > --- a/drivers/scsi/sg.c > +++ b/drivers/scsi/sg.c > @@ -480,8 +480,10 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos) > > hp = &srp->header; > old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL); > - if (!old_hdr) > - return -ENOMEM; > + if (!old_hdr) { > + retval = -ENOMEM; > + goto free_old_hdr; > + } > > old_hdr->reply_len = (int) hp->timeout; > old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */ > @@ -543,10 +545,10 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos) > } > } else > count = (old_hdr->result == 0) ? 0 : -EIO; > - sg_finish_rem_req(srp); > - sg_remove_request(sfp, srp); > retval = count; > free_old_hdr: This is no longer a fully appropriate label name > + sg_finish_rem_req(srp); > + sg_remove_request(sfp, srp); > kfree(old_hdr); > return retval; > }