From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43362) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aHVqQ-0005h3-Vf for qemu-devel@nongnu.org; Fri, 08 Jan 2016 07:08:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aHVqQ-000213-34 for qemu-devel@nongnu.org; Fri, 08 Jan 2016 07:08:38 -0500 From: P J P Date: Fri, 8 Jan 2016 17:38:21 +0530 Message-Id: <1452254901-29796-1-git-send-email-ppandit@redhat.com> Subject: [Qemu-devel] [PATCH] ide: ahci: reset ncq object to unused on error List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: Qinghao Tang , John Snow , qemu-devel@nongnu.org, Prasad J Pandit 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 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 | 2 ++ 1 file changed, 2 insertions(+) diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c index dd1912e..e359127 100644 --- a/hw/ide/ahci.c +++ b/hw/ide/ahci.c @@ -1014,6 +1014,7 @@ static void execute_ncq_command(NCQTransferState *ncq_tfs) DPRINTF(port, "error: unsupported NCQ command (0x%02x) received\n", ncq_tfs->cmd); qemu_sglist_destroy(&ncq_tfs->sglist); + ncq_tfs->used = 0; ncq_err(ncq_tfs); } } @@ -1081,6 +1082,7 @@ static void process_ncq_command(AHCIState *s, int port, uint8_t *cmd_fis, "is smaller than the requested size (0x%zx)", ncq_tfs->sglist.size, size); qemu_sglist_destroy(&ncq_tfs->sglist); + ncq_tfs->used = 0; ncq_err(ncq_tfs); ahci_trigger_irq(ad->hba, ad, PORT_IRQ_OVERFLOW); return; -- 2.4.3