libata: add SG safety checks in SFF pio transfers

[ Upstream commit 752ead44491e8c91e14d7079625c5916b30921c5 ]

Abort processing of a command if we run out of mapped data in the
SG list. This should never happen, but a previous bug caused it to
be possible. Play it safe and attempt to abort nicely if we don't
have more SG segments left.

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jens Axboe 2019-08-07 12:23:57 -06:00 committed by Greg Kroah-Hartman
parent 114bf652fb
commit d2b2a7dd72

View file

@ -703,6 +703,10 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
unsigned int offset;
unsigned char *buf;
if (!qc->cursg) {
qc->curbytes = qc->nbytes;
return;
}
if (qc->curbytes == qc->nbytes - qc->sect_size)
ap->hsm_task_state = HSM_ST_LAST;
@ -742,6 +746,8 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
if (qc->cursg_ofs == qc->cursg->length) {
qc->cursg = sg_next(qc->cursg);
if (!qc->cursg)
ap->hsm_task_state = HSM_ST_LAST;
qc->cursg_ofs = 0;
}
}