The function blk_get_request() can return NULL in some cases. There are checks on it if function is called with argumetns one of which is GFP_ATOMIC/GFP_NOIO/etc. If system couldn't find request blk_get_request() return NULL. But if there is function call with argument __GFP_WAIT the system will wait until get request or the queue becomes dead. If something kills the queue, blk_get_request() return NULL and next operations will lead to errors. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Marina Makienko <makienko@xxxxxxxxx> --- drivers/ide/ide-park.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/drivers/ide/ide-park.c b/drivers/ide/ide-park.c index 6ab9ab2..4d178bd 100644 --- a/drivers/ide/ide-park.c +++ b/drivers/ide/ide-park.c @@ -32,6 +32,8 @@ static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout) spin_unlock_irq(&hwif->lock); rq = blk_get_request(q, READ, __GFP_WAIT); + if (!rq) + goto out; rq->cmd[0] = REQ_PARK_HEADS; rq->cmd_len = 1; rq->cmd_type = REQ_TYPE_SPECIAL; -- 1.7.7 -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
