From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33965) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aHdJk-0007y1-4h for qemu-devel@nongnu.org; Fri, 08 Jan 2016 15:07:25 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aHdJj-0005ye-5x for qemu-devel@nongnu.org; Fri, 08 Jan 2016 15:07:24 -0500 References: <1452282511-4116-1-git-send-email-ppandit@redhat.com> From: John Snow Message-ID: <569016F2.3020608@redhat.com> Date: Fri, 8 Jan 2016 15:07:14 -0500 MIME-Version: 1.0 In-Reply-To: <1452282511-4116-1-git-send-email-ppandit@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2] ide: ahci: reset ncq object to unused on error List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: P J P Cc: Qinghao Tang , qemu-devel@nongnu.org, qemu-block@nongnu.org, Prasad J Pandit On 01/08/2016 02:48 PM, P J P wrote: > From: Prasad J Pandit > > When processing NCQ commands, ACHI device emulation prepares a > NCQ transfer object; To which an aio control block(aiocb) object > is assigned in 'execute_ncq_command'. In case, when the NCQ > command is invalid, the 'aiocb' object is not assigned, and NCQ > transfer object is left as 'used'. This leads to a use after > free kind of error in 'bdrv_aio_cancel_async' via 'ahci_reset_port'. > Reset NCQ transfer object to 'unused' to avoid it. > > Reported-by: Qinghao Tang > Signed-off-by: Prasad J Pandit > --- > hw/ide/ahci.c | 1 + > 1 file changed, 1 insertion(+) > > Update as per review in > -> https://lists.gnu.org/archive/html/qemu-devel/2016-01/msg01175.html > > diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c > index dd1912e..17f1cbd 100644 > --- a/hw/ide/ahci.c > +++ b/hw/ide/ahci.c > @@ -910,6 +910,7 @@ static void ncq_err(NCQTransferState *ncq_tfs) > ide_state->error = ABRT_ERR; > ide_state->status = READY_STAT | ERR_STAT; > ncq_tfs->drive->port_regs.scr_err |= (1 << ncq_tfs->tag); > + ncq_tfs->used = 0; > } > > static void ncq_finish(NCQTransferState *ncq_tfs) > Thanks, applied to my IDE tree: https://github.com/jnsnow/qemu/commits/ide https://github.com/jnsnow/qemu.git --js