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_ioctl.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/drivers/ide/ide-cd_ioctl.c b/drivers/ide/ide-cd_ioctl.c index 02caa7d..e29588f 100644 --- a/drivers/ide/ide-cd_ioctl.c +++ b/drivers/ide/ide-cd_ioctl.c @@ -304,6 +304,10 @@ int ide_cdrom_reset(struct cdrom_device_info *cdi) int ret; rq = blk_get_request(drive->queue, READ, __GFP_WAIT); + + if (!rq) + return -EIO; + rq->cmd_type = REQ_TYPE_SPECIAL; rq->cmd_flags = REQ_QUIET; ret = blk_execute_rq(drive->queue, cd->disk, rq, 0); -- 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
