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2024-05-15scsi: sr: Fix unintentional arithmetic wraparoundJustin Stitt1-2/+2
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] <TASK> [ 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 <justinstitt@google.com> Link: https://lore.kernel.org/r/20240508-b4-b4-sio-sr_select_speed-v2-1-00b68f724290@google.com Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-05-16cdrom: remove the unused driver specific disc change ioctlPaul Gortmaker1-10/+0
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 <hch@lst.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Phillip Potter <phil@philpotter.co.uk> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Link: https://lore.kernel.org/all/20220427132436.12795-2-paul.gortmaker@windriver.com Signed-off-by: Phillip Potter <phil@philpotter.co.uk> Link: https://lore.kernel.org/r/20220515205833.944139-3-phil@philpotter.co.uk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-15drivers/cdrom: improved ioctl for media change detectionLukas Prediger1-0/+11
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 <lumip@lumip.de> Link: https://lore.kernel.org/all/20210912191207.74449-1-lumip@lumip.de Signed-off-by: Phillip Potter <phil@philpotter.co.uk> Link: https://lore.kernel.org/r/20210913230942.1188-1-phil@philpotter.co.uk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-05-11docs: cdrom-standard.rst: get rid of uneeded UTF-8 charsMauro Carvalho Chehab1-15/+15
This file was converted from a LaTeX one. The conversion used some UTF-8 characters at the literal blocks. Replace them by normal ASCII characters. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Acked-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/79c3f482da17ea48d69b6e6ad1b7fb102b9dd7bf.1620744606.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-08-13Merge tag 'docs-5.9-2' of git://git.lwn.net/linuxLinus Torvalds1-2/+2
Pull documentation fixes from Jonathan Corbet: "A handful of obvious fixes that wandered in during the merge window" * tag 'docs-5.9-2' of git://git.lwn.net/linux: Documentation/locking/locktypes: fix the typo doc/zh_CN: resolve undefined label warning in admin-guide index doc/zh_CN: fix title heading markup in admin-guide cpu-load docs: remove the 2.6 "Upgrading I2C Drivers" guide docs: Correct the release date of 5.2 stable mailmap: Update comments for with format and more detalis docs: cdrom: Fix a typo and rst markup Doc: admin-guide: use correct legends in kernel-parameters.txt Documentation/features: refresh RISC-V arch support files documentation: coccinelle: Improve command example for make C={1,2} Core-api: Documentation: Replace deprecated :c:func: Usage Dev-tools: Documentation: Replace deprecated :c:func: Usage Filesystems: Documentation: Replace deprecated :c:func: Usage docs: trace: fix a typo
2020-08-11docs: cdrom: Fix a typo and rst markupRemi Andruccioli1-2/+2
"The capability fags" should be "The capability flags". In rst markup, a incorrect markup expression is causing bad rendering in Sphinx output. Replace the erroneous single quote by a backquote. Signed-off-by: Remi Andruccioli <remi.andruccioli@gmail.com> Link: https://lore.kernel.org/r/20200808163123.17643-1-remi.andruccioli@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-09cdrom: remove the unused cdrom_media_changed functionChristoph Hellwig1-17/+1
As well as the ->media_changed method. All these are left over from before the drivers were switched over to the check_events scheme. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-14docs: cdrom: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-0/+1063
The stuff there is almost already at ReST format. A conversion for them is trivial: just add a missing titles and fix some scape codes for them to match ReST syntax. While here, rename the cdrom-standard.txt, with was converted from LaTeX to ReST on the previous patch, and add it to the index file. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>