3.2-stable review patch. If anyone has any objections, please let me know.
------------------ From: Vivek Goyal <[email protected]> commit 3f9a5aabd0a9fe0e0cd308506f48963d79169aa7 upstream. add_disk() takes gendisk reference on request queue. If driver failed during initialization and never called add_disk() then that extra reference is not taken. That reference is put in put_disk(). floppy driver allocates the disk, allocates queue, sets disk->queue and then relizes that floppy controller is not present. It tries to tear down everything and tries to put a reference down in put_disk() which was never taken. In such error cases cleanup disk->queue before calling put_disk() so that we never try to put down a reference which was never taken in first place. Reported-and-tested-by: Suresh Jayaraman <[email protected]> Tested-by: Dirk Gouders <[email protected]> Signed-off-by: Vivek Goyal <[email protected]> Acked-by: Tejun Heo <[email protected]> Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- drivers/block/floppy.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 510fb10..401ba78 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -4368,8 +4368,14 @@ out_unreg_blkdev: out_put_disk: while (dr--) { del_timer_sync(&motor_off_timer[dr]); - if (disks[dr]->queue) + if (disks[dr]->queue) { blk_cleanup_queue(disks[dr]->queue); + /* + * put_disk() is not paired with add_disk() and + * will put queue reference one extra time. fix it. + */ + disks[dr]->queue = NULL; + } put_disk(disks[dr]); } return err; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
