kernel/drivers/cdrom/cdrom.c, branch linux-6.9.y

cdrom: rearrange last_media_change check to avoid unintentional overflow

2024-07-11T10:51:06Z

[ Upstream commit efb905aeb44b0e99c0e6b07865b1885ae0471ebf ] When running syzkaller with the newly reintroduced signed integer wrap sanitizer we encounter this splat: [ 366.015950] UBSAN: signed-integer-overflow in ../drivers/cdrom/cdrom.c:2361:33 [ 366.021089] -9223372036854775808 - 346321 cannot be represented in type '__s64' (aka 'long long') [ 366.025894] program syz-executor.4 is using a deprecated SCSI ioctl, please convert it to SG_IO [ 366.027502] CPU: 5 PID: 28472 Comm: syz-executor.7 Not tainted 6.8.0-rc2-00035-gb3ef86b5a957 #1 [ 366.027512] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 366.027518] Call Trace: [ 366.027523] [ 366.027533] dump_stack_lvl+0x93/0xd0 [ 366.027899] handle_overflow+0x171/0x1b0 [ 366.038787] ata1.00: invalid multi_count 32 ignored [ 366.043924] cdrom_ioctl+0x2c3f/0x2d10 [ 366.063932] ? __pm_runtime_resume+0xe6/0x130 [ 366.071923] sr_block_ioctl+0x15d/0x1d0 [ 366.074624] ? __pfx_sr_block_ioctl+0x10/0x10 [ 366.077642] blkdev_ioctl+0x419/0x500 [ 366.080231] ? __pfx_blkdev_ioctl+0x10/0x10 ... Historically, the signed integer overflow sanitizer did not work in the kernel due to its interaction with `-fwrapv` but this has since been changed [1] in the newest version of Clang. It was re-enabled in the kernel with Commit 557f8c582a9ba8ab ("ubsan: Reintroduce signed overflow sanitizer"). Let's rearrange the check to not perform any arithmetic, thus not tripping the sanitizer. Link: https://github.com/llvm/llvm-project/pull/82432 [1] Closes: https://github.com/KSPP/linux/issues/354 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt Link: https://lore.kernel.org/lkml/20240507-b4-sio-ata1-v1-1-810ffac6080a@google.com Reviewed-by: Phillip Potter Link: https://lore.kernel.org/lkml/ZjqU0fbzHrlnad8D@equinox Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20240507222520.1445-2-phil@philpotter.co.uk Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

cdrom: Remove now superfluous sentinel element from ctl_table array

2023-10-03T02:04:58Z

This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) Remove sentinel element from cdrom_table Signed-off-by: Joel Granados Link: https://lore.kernel.org/lkml/20231002-jag-sysctl_remove_empty_elem_drivers-v2-1-02dd0d46f71e@samsung.com Reviewed-by: Phillip Potter Link: https://lore.kernel.org/lkml/20231002214528.15529-1-phil@philpotter.co.uk Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20231002220203.15637-2-phil@philpotter.co.uk Signed-off-by: Jens Axboe

cdrom: Fix spectre-v1 gadget

2023-06-22T13:48:08Z

This patch fixes a spectre-v1 gadget in cdrom. The gadget could be triggered by speculatively bypassing the cdi->capacity check. Signed-off-by: Jordy Zomer Link: https://lore.kernel.org/all/20230612110040.849318-2-jordyzomer@google.com Reviewed-by: Phillip Potter Link: https://lore.kernel.org/all/ZI1+1OG9Ut1MqsUC@equinox Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20230617113828.1230-2-phil@philpotter.co.uk Signed-off-by: Jens Axboe

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

2023-06-12T14:04:05Z

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

cdrom: remove the unused mode argument to cdrom_release

2023-06-12T14:04:03Z

Signed-off-by: Christoph Hellwig Reviewed-by: Phillip Potter Reviewed-by: Hannes Reinecke Acked-by: Christian Brauner Link: https://lore.kernel.org/r/20230608110258.189493-7-hch@lst.de Signed-off-by: Jens Axboe

cdrom: track if a cdrom_device_info was opened for data

2023-06-12T14:04:03Z

Set a flag when a cdrom_device_info is opened for writing, instead of trying to figure out this at release time. This will allow to eventually remove the mode argument to the ->release block_device_operation as nothing but the CDROM drivers uses that argument. Signed-off-by: Christoph Hellwig Reviewed-by: Phillip Potter Acked-by: Christian Brauner Reviewed-by: Hannes Reinecke Link: https://lore.kernel.org/r/20230608110258.189493-6-hch@lst.de Signed-off-by: Jens Axboe

cdrom: remove the unused cdrom_close_write release code

2023-06-12T14:04:03Z

cdrom_close_write is empty, and the for_data flag it is keyed off is never set. Remove all this clutter. Signed-off-by: Christoph Hellwig Reviewed-by: Phillip Potter Reviewed-by: Hannes Reinecke Acked-by: Christian Brauner Link: https://lore.kernel.org/r/20230608110258.189493-5-hch@lst.de Signed-off-by: Jens Axboe

cdrom: remove the unused mode argument to cdrom_ioctl

2023-06-12T14:04:03Z

cdrom: remove the unused bdev argument to cdrom_open

2023-06-12T14:04:03Z

cdrom: remove obsolete TODO list

2022-05-16T00:31:28Z

The TODO list in drivers/cdrom/cdrom.c has a single entry containing obsolete information, unchanged since the first git commit over 17 years ago, and probably longer. Remove this list from the comment to prevent confusion in future. Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20220515205833.944139-6-phil@philpotter.co.uk Signed-off-by: Jens Axboe