From bbdc74dc19e09ac4e71bfb219596b3d5bc786720 Mon Sep 17 00:00:00 2001 From: Grzegorz Sluja Date: Thu, 13 Jul 2017 11:17:58 +0200 Subject: mmc: block: Prevent new req entering queue after its cleanup The commit 304419d8a7e9 ("mmc: core: Allocate per-request data using the block layer core"), refactored the mechanism of queue handling, but also made mmc_init_request() to be called after mmc_cleanup_queue(). This triggers a null pointer dereference: [ 683.123791] BUG: unable to handle kernel NULL pointer dereference at (null) [ 683.123801] IP: mmc_init_request+0x2c/0xf0 [mmc_block] ... [ 683.123905] Call Trace: [ 683.123913] alloc_request_size+0x4f/0x70 [ 683.123919] mempool_alloc+0x5f/0x150 [ 683.123925] ? __enqueue_entity+0x6c/0x70 [ 683.123928] get_request+0x3ad/0x720 [ 683.123933] ? prepare_to_wait_event+0x110/0x110 [ 683.123937] blk_queue_bio+0xc1/0x3a0 [ 683.123940] generic_make_request+0xf8/0x2a0 [ 683.123942] submit_bio+0x75/0x150 [ 683.123947] submit_bio_wait+0x51/0x70 [ 683.123951] blkdev_issue_flush+0x5c/0x90 [ 683.123956] ext4_sync_fs+0x171/0x1b0 [ 683.123961] sync_filesystem+0x73/0x90 [ 683.123965] fsync_bdev+0x24/0x50 [ 683.123971] invalidate_partition+0x24/0x50 [ 683.123973] del_gendisk+0xb2/0x2a0 [ 683.123977] mmc_blk_remove_req.part.38+0x71/0xa0 [mmc_block] [ 683.123980] mmc_blk_remove+0xba/0x190 [mmc_block] [ 683.123990] mmc_bus_remove+0x1a/0x20 [mmc_core] [ 683.123995] device_release_driver_internal+0x141/0x200 [ 683.123999] device_release_driver+0x12/0x20 [ 683.124001] bus_remove_device+0xfd/0x170 [ 683.124004] device_del+0x1e8/0x330 [ 683.124012] mmc_remove_card+0x60/0xc0 [mmc_core] [ 683.124019] mmc_remove+0x19/0x30 [mmc_core] [ 683.124025] mmc_stop_host+0xfb/0x1a0 [mmc_core] [ 683.124032] mmc_remove_host+0x1a/0x40 [mmc_core] [ 683.124037] sdhci_remove_host+0x2e/0x1c0 [mmc_sdhci] [ 683.124042] sdhci_pci_remove_slot+0x3f/0x80 [sdhci_pci] [ 683.124045] sdhci_pci_remove+0x39/0x70 [sdhci_pci] [ 683.124049] pci_device_remove+0x39/0xc0 [ 683.124052] device_release_driver_internal+0x141/0x200 [ 683.124056] driver_detach+0x3f/0x80 [ 683.124059] bus_remove_driver+0x55/0xd0 [ 683.124062] driver_unregister+0x2c/0x50 [ 683.124065] pci_unregister_driver+0x29/0x90 [ 683.124069] sdhci_driver_exit+0x10/0x4f3 [sdhci_pci] [ 683.124073] SyS_delete_module+0x171/0x250 [ 683.124078] entry_SYSCALL_64_fastpath+0x1e/0xa9 Fix this by setting the queue DYING flag before cleanup the queue, as it prevents new reqs from entering the queue. Signed-off-by: Grzegorz Sluja Signed-off-by: Linus Walleij Fixes: 304419d8a7e9 ("mmc: core: Allocate per-request data using the...") [Ulf: Updated the changelog] Signed-off-by: Ulf Hansson --- drivers/mmc/core/block.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers') diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index e0363223996e..8ac59dc80f23 100644 --- a/drivers/mmc/core/block.c +++ b/drivers/mmc/core/block.c @@ -2170,6 +2170,7 @@ static void mmc_blk_remove_req(struct mmc_blk_data *md) * from being accepted. */ card = md->queue.card; + blk_set_queue_dying(md->queue.queue); mmc_cleanup_queue(&md->queue); if (md->disk->flags & GENHD_FL_UP) { device_remove_file(disk_to_dev(md->disk), &md->force_ro); -- cgit v1.2.3