From 4ab0359a8ae182a7ac5c99609667273167703fab Mon Sep 17 00:00:00 2001 From: Prasad J Pandit Date: Mon, 11 Jan 2016 14:10:42 -0500 Subject: [PATCH] ide: ahci: reset ncq object to unused on error When processing NCQ commands, AHCI 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. [Maintainer edit: s/ACHI/AHCI/ in the commit message. --js] Reported-by: Qinghao Tang Signed-off-by: Prasad J Pandit Reviewed-by: John Snow Message-id: 1452282511-4116-1-git-send-email-ppandit@redhat.com Signed-off-by: John Snow Upstream-Status: Backport http://git.qemu.org/?p=qemu.git;a=commit;h=4ab0359a8ae182a7ac5c99609667273167703fab CVE: CVE-2016-1568 [Yocto # 9013] Signed-off-by: Armin Kuster --- hw/ide/ahci.c | 1 + 1 file changed, 1 insertion(+) Index: qemu-2.5.0/hw/ide/ahci.c =================================================================== --- qemu-2.5.0.orig/hw/ide/ahci.c +++ qemu-2.5.0/hw/ide/ahci.c @@ -910,6 +910,7 @@ static void ncq_err(NCQTransferState *nc 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)