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-cd.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c index 8126824..9dd575d 100644 --- a/drivers/ide/ide-cd.c +++ b/drivers/ide/ide-cd.c @@ -443,6 +443,9 @@ int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd, rq = blk_get_request(drive->queue, write, __GFP_WAIT); + if (!rq) + return -EIO; + memcpy(rq->cmd, cmd, BLK_MAX_CDB); rq->cmd_type = REQ_TYPE_ATA_PC; rq->sense = sense; -- 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
