kernel/linux.git/drivers/cdrom/cdrom.c, branch v6.1.168

cdrom: rearrange last_media_change check to avoid unintentional overflow

2024-07-11T10:47:10+00:00

[ 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 obsolete TODO list

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

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

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

cdrom: make EXPORT_SYMBOL follow exported function

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

Currently, some EXPORT_SYMBOL declarations do not follow the exported function, which affects the readability of the code. To maintain consistency, move these EXPORT_SYMBOL declarations to the correct position to improve the readability of the code. Signed-off-by: Enze Li Link: https://lore.kernel.org/all/20220406090337.1116708-1-lienze@kylinos.cn Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20220515205833.944139-2-phil@philpotter.co.uk Signed-off-by: Jens Axboe

cdrom: remove unused variable

2022-04-06T14:47:52+00:00

The clang static analyzer reports the following warning, File: drivers/cdrom/cdrom.c Warning: line 1380, column 7 Although the value stored to 'status' is used in enclosing expression, the value is never actually read from 'status' Remove the unused variable to eliminate the warning. Signed-off-by: Enze Li Link: https://lore.kernel.org/all/20220401032623.293666-1-lienze@kylinos.cn Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20220401211842.2088096-1-phil@philpotter.co.uk Signed-off-by: Jens Axboe

scsi: core: Remove

2022-03-02T03:21:50+00:00

This header is empty now except for an include of , so remove it. Link: https://lore.kernel.org/r/20220224175552.988286-9-hch@lst.de Reviewed-by: Bart Van Assche Reviewed-by: John Garry Signed-off-by: Christoph Hellwig Signed-off-by: Martin K. Petersen

cdrom: simplify subdirectory registration with register_sysctl()

2022-01-22T06:33:35+00:00

There is no need to user boiler plate code to specify a set of base directories we're going to stuff sysctls under. Simplify this by using register_sysctl() and specifying the directory path directly. // pycocci sysctl-subdir-register-sysctl-simplify.cocci PATH @c1@ expression E1; identifier subdir, sysctls; @@ static struct ctl_table subdir[] = { { .procname = E1, .maxlen = 0, .mode = 0555, .child = sysctls, }, { } }; @c2@ identifier c1.subdir; expression E2; identifier base; @@ static struct ctl_table base[] = { { .procname = E2, .maxlen = 0, .mode = 0555, .child = subdir, }, { } }; @c3@ identifier c2.base; identifier header; @@ header = register_sysctl_table(base); @r1 depends on c1 && c2 && c3@ expression c1.E1; identifier c1.subdir, c1.sysctls; @@ -static struct ctl_table subdir[] = { - { - .procname = E1, - .maxlen = 0, - .mode = 0555, - .child = sysctls, - }, - { } -}; @r2 depends on c1 && c2 && c3@ identifier c1.subdir; expression c2.E2; identifier c2.base; @@ -static struct ctl_table base[] = { - { - .procname = E2, - .maxlen = 0, - .mode = 0555, - .child = subdir, - }, - { } -}; @initialize:python@ @@ def make_my_fresh_expression(s1, s2): return '"' + s1.strip('"') + "/" + s2.strip('"') + '"' @r3 depends on c1 && c2 && c3@ expression c1.E1; identifier c1.sysctls; expression c2.E2; identifier c2.base; identifier c3.header; fresh identifier E3 = script:python(E2, E1) { make_my_fresh_expression(E2, E1) }; @@ header = -register_sysctl_table(base); +register_sysctl(E3, sysctls); Generated-by: Coccinelle SmPL Link: https://lkml.kernel.org/r/20211123202422.819032-8-mcgrof@kernel.org Signed-off-by: Luis Chamberlain Cc: Al Viro Cc: Amir Goldstein Cc: Andy Shevchenko Cc: Antti Palosaari Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Benjamin LaHaise Cc: Clemens Ladisch Cc: David Airlie Cc: "Eric W. Biederman" Cc: Greg Kroah-Hartman Cc: Iurii Zaikin Cc: Jani Nikula Cc: Jan Kara Cc: Joel Becker Cc: Joonas Lahtinen Cc: Joseph Qi Cc: Julia Lawall Cc: Kees Cook Cc: Lukas Middendorf Cc: Mark Fasheh Cc: Paul Turner Cc: Peter Zijlstra Cc: Petr Mladek Cc: Phillip Potter Cc: Qing Wang Cc: Rodrigo Vivi Cc: Sebastian Reichel Cc: Sergey Senozhatsky Cc: Stephen Kitt Cc: Tetsuo Handa Cc: Xiaoming Ni Cc: Douglas Gilbert Cc: James E.J. Bottomley Cc: Jani Nikula Cc: John Ogness Cc: Martin K. Petersen Cc: "Rafael J. Wysocki" Cc: Steven Rostedt (VMware) Cc: Suren Baghdasaryan Cc: "Theodore Ts'o" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cdrom: Remove redundant variable and its assignment

2021-10-21T14:23:09+00:00

Variable is not used in functions, and its assignment is redundant too. So it should be deleted. Also the inner-most set of parentheses is no longer needed. The clang_analyzer complains as follows: drivers/cdrom/cdrom.c:877: warning: Although the value stored to 'ret' is used in the enclosing expression, the value is never actually read from 'ret'. Reported-by: Zeal Robot Signed-off-by: luo penghao Link: https://lore.kernel.org/all/20211020024229.1036219-1-luo.penghao@zte.com.cn Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20211021074621.901-1-phil@philpotter.co.uk Signed-off-by: Jens Axboe

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

scsi: sr: cdrom: Move cdrom_read_cdda_bpc() into the sr driver

2021-07-31T02:13:09+00:00

cdrom_read_cdda_bpc() relies on sending SCSI command to the low level driver using a REQ_OP_SCSI_IN request. This isn't generic block layer functionality, so move the actual low-level code into the sr driver and call it through a new read_cdda_bpc method in the cdrom_device_ops structure. With this the CDROM code does not have to pull in scsi_normalize_sense() and depend on CONFIG_SCSI_COMMON. Link: https://lore.kernel.org/r/20210730072752.GB23847%40lst.de Tested-by: Anders Roxell Signed-off-by: Christoph Hellwig Signed-off-by: Martin K. Petersen