From: Jens Axboe axboe@kernel.dk
[ 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 --- drivers/ata/libata-sff.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c index cc2f2e35f4c2e..8c36ff0c2dd49 100644 --- a/drivers/ata/libata-sff.c +++ b/drivers/ata/libata-sff.c @@ -704,6 +704,10 @@ 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;
@@ -729,6 +733,8 @@ 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; } }