kernel/linux.git/Documentation/cdrom, branch v6.18.21

cdrom: Call cdrom_mrw_exit from cdrom_release function

2025-07-23T01:10:17+00:00

Remove the cdrom_mrw_exit call from unregister_cdrom, as it invokes block commands that can fail due to a NULL pointer dereference from the call happening too late, during the unloading of the driver (e.g. unplugging of USB optical drives). Instead perform the call inside cdrom_release, thus also removing the need for the exit function pointer inside the cdrom_device_info struct. Reported-by: Sergey Senozhatsky Closes: https://lore.kernel.org/linux-block/uxgzea5ibqxygv3x7i4ojbpvcpv2wziorvb3ns5cdtyvobyn7h@y4g4l5ezv2ec Suggested-by: Jens Axboe Link: https://lore.kernel.org/linux-block/6686fe78-a050-4a1d-aa27-b7bf7ca6e912@kernel.dk Tested-by: Phillip Potter Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20250722231900.1164-2-phil@philpotter.co.uk Signed-off-by: Jens Axboe

Documentation: remove reference to pktcdvd in cdrom documentation

2025-07-08T13:57:02+00:00

pktcdvd got killed in a previous commit, remove the reference to it as well in the cdrom documentation. Fixes: 1cea5180f2f8 ("block: remove pktcdvd driver") Reported-by: Stephen Rothwell Signed-off-by: Jens Axboe

block: remove pktcdvd driver

2025-07-07T13:02:42+00:00

This driver has long outlived it's utility, and it's broken and unloved. The main use case for this was direct mount with UDF of cd-rw drives that required 32kb packets. It would collect writes into that size and write them out in multiples of that. That's not a common use case anymore, the world has moved on from those kinds of media. To make matters worse, it's actively breaking setups where it's not even required or useful. Link: https://lore.kernel.org/linux-block/fxg6dksau4jsk3u5xldlyo2m7qgiux6vtdrz5rywseotsouqdv@urcrwz6qtd3r/ Link: https://lore.kernel.org/linux-block/dcc4836e-6da9-4208-ad27-bbd44b3a2063@kernel.dk/ Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

scsi: sr: Fix unintentional arithmetic wraparound

2024-05-15T14:05:24+00:00

Running syzkaller with the newly reintroduced signed integer overflow sanitizer produces this report: [ 65.194362] ------------[ cut here ]------------ [ 65.197752] UBSAN: signed-integer-overflow in ../drivers/scsi/sr_ioctl.c:436:9 [ 65.203607] -2147483648 * 177 cannot be represented in type 'int' [ 65.207911] CPU: 2 PID: 10416 Comm: syz-executor.1 Not tainted 6.8.0-rc2-00035-gb3ef86b5a957 #1 [ 65.213585] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 65.219923] Call Trace: [ 65.221556] [ 65.223029] dump_stack_lvl+0x93/0xd0 [ 65.225573] handle_overflow+0x171/0x1b0 [ 65.228219] sr_select_speed+0xeb/0xf0 [ 65.230786] ? __pm_runtime_resume+0xe6/0x130 [ 65.233606] sr_block_ioctl+0x15d/0x1d0 ... 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 557f8c582a9b ("ubsan: Reintroduce signed overflow sanitizer"). Firstly, let's change the type of "speed" to unsigned long as sr_select_speed()'s only caller passes in an unsigned long anyways. $ git grep '\.select_speed' | drivers/scsi/sr.c: .select_speed = sr_select_speed, ... | static int cdrom_ioctl_select_speed(struct cdrom_device_info *cdi, | unsigned long arg) | { | ... | return cdi->ops->select_speed(cdi, arg); | } Next, let's add an extra check to make sure we don't exceed 0xffff/177 (350) since 0xffff is the max speed. This has two benefits: 1) we deal with integer overflow before it happens and 2) we properly respect the max speed of 0xffff. There are some "magic" numbers here but I did not want to change more than what was necessary. Link: https://github.com/llvm/llvm-project/pull/82432 [1] Closes: https://github.com/KSPP/linux/issues/357 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt Link: https://lore.kernel.org/r/20240508-b4-b4-sio-sr_select_speed-v2-1-00b68f724290@google.com Reviewed-by: Kees Cook Signed-off-by: Martin K. Petersen

Documentation: use capitalization for chapters and acronyms

2023-05-16T18:49:31+00:00

Use capital letters in acronyms for CD-ROM, FPGA, and PCMCIA. Use capital letter in the first word of chapter headings for Locking, Timers, and "Brief tutorial on CRC computation". Signed-off-by: Randy Dunlap Cc: Moritz Fischer Cc: Wu Hao Cc: Tom Rix Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Will Deacon Cc: Waiman Long Cc: Boqun Feng Cc: Dominik Brodowski Cc: Thomas Gleixner Acked-by: Xu Yilun Reviewed-by: Phillip Potter Link: https://lore.kernel.org/r/20230516001518.14514-1-rdunlap@infradead.org Signed-off-by: Jonathan Corbet

Merge tag 'docs-5.19' of git://git.lwn.net/linux

2022-05-25T18:17:41+00:00

Pull documentation updates from Jonathan Corbet: "It was a moderately busy cycle for documentation; highlights include: - After a long period of inactivity, the Japanese translations are seeing some much-needed maintenance and updating. - Reworked IOMMU documentation - Some new documentation for static-analysis tools - A new overall structure for the memory-management documentation. This is an LSFMM outcome that, it is hoped, will help encourage developers to fill in the many gaps. Optimism is eternal...but hopefully it will work. - More Chinese translations. Plus the usual typo fixes, updates, etc" * tag 'docs-5.19' of git://git.lwn.net/linux: (70 commits) docs: pdfdocs: Add space for chapter counts >= 100 in TOC docs/zh_CN: Add dev-tools/gdb-kernel-debugging.rst Chinese translation input: Docs: correct ntrig.rst typo input: Docs: correct atarikbd.rst typos MAINTAINERS: Become the docs/zh_CN maintainer docs/zh_CN: fix devicetree usage-model translation mm,doc: Add new documentation structure Documentation: drop more IDE boot options and ide-cd.rst Documentation/process: use scripts/get_maintainer.pl on patches MAINTAINERS: Add entry for DOCUMENTATION/JAPANESE docs/trans/ja_JP/howto: Don't mention specific kernel versions docs/ja_JP/SubmittingPatches: Request summaries for commit references docs/ja_JP/SubmittingPatches: Add Suggested-by as a standard signature docs/ja_JP/SubmittingPatches: Randy has moved docs/ja_JP/SubmittingPatches: Suggest the use of scripts/get_maintainer.pl docs/ja_JP/SubmittingPatches: Update GregKH links Documentation/sysctl: document max_rcu_stall_to_panic Documentation: add missing angle bracket in cgroup-v2 doc Documentation: dev-tools: use literal block instead of code-block docs/zh_CN: add vm numa translation ...

cdrom: remove the unused driver specific disc change ioctl

2022-05-16T00:31:28+00:00

This was only used by the ide-cd driver, which went away in commit b7fb14d3ac63 ("ide: remove the legacy ide driver") so we might as well take advantage of that and get rid of this hook as well. Cc: Christoph Hellwig Cc: Jens Axboe Cc: Phillip Potter Signed-off-by: Paul Gortmaker Link: https://lore.kernel.org/all/20220427132436.12795-2-paul.gortmaker@windriver.com Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20220515205833.944139-3-phil@philpotter.co.uk Signed-off-by: Jens Axboe

Documentation: drop more IDE boot options and ide-cd.rst

2022-05-09T22:20:07+00:00

Drop ide-* command line options. Drop cdrom/ide-cd.rst documentation. Fixes: 898ee22c32be ("Drop Documentation/ide/") Signed-off-by: Randy Dunlap Cc: Jens Axboe Cc: Christoph Hellwig Acked-by: Damien Le Moal Acked-by: Phillip Potter Link: https://lore.kernel.org/r/20220424033701.7988-1-rdunlap@infradead.org [jc: also deleted reference from cdrom/index.rst] Signed-off-by: Jonathan Corbet

Documentation: Fix links for udftools project and pktcdvd tool

2022-02-15T23:15:33+00:00

Signed-off-by: Pali Rohár Link: https://lore.kernel.org/r/20220210192200.30828-1-pali@kernel.org Signed-off-by: Jonathan Corbet

drivers/cdrom: improved ioctl for media change detection

2021-09-15T02:05:26+00:00

The current implementation of the CDROM_MEDIA_CHANGED ioctl relies on global state, meaning that only one process can detect a disc change while the ioctl call will return 0 for other calling processes afterwards (see bug 213267). This introduces a new cdrom ioctl, CDROM_TIMED_MEDIA_CHANGE, that works by maintaining a timestamp of the last detected disc change instead of a boolean flag: Processes calling this ioctl command can provide a timestamp of the last disc change known to them and receive an indication whether the disc was changed since then and the updated timestamp. I considered fixing the buggy behavior in the original CDROM_MEDIA_CHANGED ioctl but that would require maintaining state for each calling process in the kernel, which seems like a worse solution than introducing this new ioctl. Signed-off-by: Lukas Prediger Link: https://lore.kernel.org/all/20210912191207.74449-1-lumip@lumip.de Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20210913230942.1188-1-phil@philpotter.co.uk Signed-off-by: Jens Axboe