kernel/linux.git/drivers/mtd/mtd_blkdevs.c, branch v6.6.132

mtd: Fix gluebi NULL pointer dereference caused by ftl notifier

2024-01-25T23:35:15+00:00

[ Upstream commit a43bdc376deab5fff1ceb93dca55bcab8dbdc1d6 ] If both ftl.ko and gluebi.ko are loaded, the notifier of ftl triggers NULL pointer dereference when trying to access ‘gluebi->desc’ in gluebi_read(). ubi_gluebi_init ubi_register_volume_notifier ubi_enumerate_volumes ubi_notify_all gluebi_notify nb->notifier_call() gluebi_create mtd_device_register mtd_device_parse_register add_mtd_device blktrans_notify_add not->add() ftl_add_mtd tr->add_mtd() scan_header mtd_read mtd_read_oob mtd_read_oob_std gluebi_read mtd->read() gluebi->desc - NULL Detailed reproduction information available at the Link [1], In the normal case, obtain gluebi->desc in the gluebi_get_device(), and access gluebi->desc in the gluebi_read(). However, gluebi_get_device() is not executed in advance in the ftl_add_mtd() process, which leads to NULL pointer dereference. The solution for the gluebi module is to run jffs2 on the UBI volume without considering working with ftl or mtdblock [2]. Therefore, this problem can be avoided by preventing gluebi from creating the mtdblock device after creating mtd partition of the type MTD_UBIVOLUME. Fixes: 2ba3d76a1e29 ("UBI: make gluebi a separate module") Link: https://bugzilla.kernel.org/show_bug.cgi?id=217992 [1] Link: https://lore.kernel.org/lkml/441107100.23734.1697904580252.JavaMail.zimbra@nod.at/ [2] Signed-off-by: ZhaoLong Wang Reviewed-by: Zhihao Cheng Acked-by: Richard Weinberger Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20231220024619.2138625-1-wangzhaolong1@huawei.com Signed-off-by: Sasha Levin

block: replace fmode_t with a block-specific type for block open flags

2023-06-12T14:04:05+00:00

The only overlap between the block open flags mapped into the fmode_t and other uses of fmode_t are FMODE_READ and FMODE_WRITE. Define a new blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and ->ioctl and stop abusing fmode_t. Signed-off-by: Christoph Hellwig Acked-by: Jack Wang [rnbd] Reviewed-by: Hannes Reinecke Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de Signed-off-by: Jens Axboe

mtd: block: use a simple bool to track open for write

2023-06-12T14:04:04+00:00

Instead of propagating the fmode_t, just use a bool to track if a mtd block device was opened for writing. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Acked-by: Christian Brauner Acked-by: Richard Weinberger Link: https://lore.kernel.org/r/20230608110258.189493-23-hch@lst.de Signed-off-by: Jens Axboe

block: remove the unused mode argument to ->release

2023-06-12T14:04:04+00:00

The mode argument to the ->release block_device_operation is never used, so remove it. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Acked-by: Christian Brauner Acked-by: Jack Wang [rnbd] Link: https://lore.kernel.org/r/20230608110258.189493-10-hch@lst.de Signed-off-by: Jens Axboe

block: pass a gendisk to ->open

2023-06-12T14:04:04+00:00

->open is only called on the whole device. Make that explicit by passing a gendisk instead of the block_device. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Acked-by: Christian Brauner Acked-by: Jack Wang [rnbd] Link: https://lore.kernel.org/r/20230608110258.189493-9-hch@lst.de Signed-off-by: Jens Axboe

block: remove blk_cleanup_disk

2022-06-28T12:33:15+00:00

blk_cleanup_disk is nothing but a trivial wrapper for put_disk now, so remove it. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Link: https://lore.kernel.org/r/20220619060552.1850436-7-hch@lst.de Signed-off-by: Jens Axboe

block: remove QUEUE_FLAG_DISCARD

2022-04-18T01:49:59+00:00

Just use a non-zero max_discard_sectors as an indicator for discard support, similar to what is done for write zeroes. The only places where needs special attention is the RAID5 driver, which must clear discard support for security reasons by default, even if the default stacking rules would allow for it. Signed-off-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Acked-by: Christoph Böhmwalder [drbd] Acked-by: Jan Höppner [s390] Acked-by: Coly Li [bcache] Acked-by: David Sterba [btrfs] Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de Signed-off-by: Jens Axboe

mtd_blkdevs: avoid soft lockups with some mtd/spi devices

2022-01-26T10:43:02+00:00

With some spi devices, the heavy cpu usage due to polling the spi registers may lead to netdev timeouts, RCU complaints, etc. This can be acute in the absence of CONFIG_PREEMPT. This patch allows to give enough breathing room to avoid those incorrectly detected netdev timeouts for example. Example splat on 5.10.92: [ 828.399306] rcu: INFO: rcu_sched self-detected stall on CPU ... [ 828.419245] Task dump for CPU 1: [ 828.422465] task:kworker/1:1H state:R running task on cpu 1 stack: 0 pid: 76 ppid: 2 flags:0x0000002a [ 828.433132] Workqueue: kblockd blk_mq_run_work_fn [ 828.437820] Call trace: ... [ 828.512267] spi_mem_exec_op+0x4d0/0xde0 [ 828.516184] spi_mem_dirmap_read+0x180/0x39c [ 828.520443] spi_nor_read_data+0x428/0x7e8 [ 828.524523] spi_nor_read+0x154/0x214 [ 828.528172] mtd_read_oob+0x440/0x714 [ 828.531815] mtd_read+0xac/0x120 [ 828.535030] mtdblock_readsect+0x178/0x230 [ 828.539102] mtd_blktrans_work+0x9fc/0xf28 [ 828.543177] mtd_queue_rq+0x1ac/0x2e4 [ 828.546827] blk_mq_dispatch_rq_list+0x2cc/0xa44 [ 828.551419] blk_mq_do_dispatch_sched+0xb0/0x7cc [ 828.556010] __blk_mq_sched_dispatch_requests+0x350/0x494 [ 828.561372] blk_mq_sched_dispatch_requests+0xac/0xe4 [ 828.566387] __blk_mq_run_hw_queue+0x130/0x254 [ 828.570806] blk_mq_run_work_fn+0x50/0x60 [ 828.574814] process_one_work+0x578/0xf1c [ 828.578814] worker_thread+0x5dc/0xea0 [ 828.582547] kthread+0x270/0x2d4 [ 828.585765] ret_from_fork+0x10/0x30 Signed-off-by: David Decotigny Reviewed-by: Richard Weinberger Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20220126101120.676021-1-decot+git@google.com

mtd_blkdevs: don't scan partitions for plain mtdblock

2021-12-12T19:19:10+00:00

mtdblock / mtdblock_ro set part_bits to 0 and thus nevever scanned partitions. Restore that behavior by setting the GENHD_FL_NO_PART flag. Fixes: 1ebe2e5f9d68e94c ("block: remove GENHD_FL_EXT_DEVT") Reported-by: Geert Uytterhoeven Signed-off-by: Christoph Hellwig Tested-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20211206070409.2836165-1-hch@lst.de Signed-off-by: Jens Axboe

mtd_blkdevs: remove the sector out of range check in do_blktrans_request

2021-11-29T13:41:29+00:00

The block layer already performs this check, no need to duplicate it in the driver. Signed-off-by: Christoph Hellwig Reviewed-by: Miquel Raynal Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20211126121802.2090656-2-hch@lst.de Signed-off-by: Jens Axboe