233087ca06
Minh Yuan reported a concurrency use-after-free issue in the floppy code between raw_cmd_ioctl and seek_interrupt. [ It turns out this has been around, and that others have reported the KASAN splats over the years, but Minh Yuan had a reproducer for it and so gets primary credit for reporting it for this fix - Linus ] The problem is, this driver tends to break very easily and nowadays, nobody is expected to use FDRAWCMD anyway since it was used to manipulate non-standard formats. The risk of breaking the driver is higher than the risk presented by this race, and accessing the device requires privileges anyway. Let's just add a config option to completely disable this ioctl and leave it disabled by default. Distros shouldn't use it, and only those running on antique hardware might need to enable it. Link: https://lore.kernel.org/all/000000000000b71cdd05d703f6bf@google.com/ Link: https://lore.kernel.org/lkml/CAKcFiNC=MfYVW-Jt9A3=FPJpTwCD2PL_ULNCpsCVE5s8ZeBQgQ@mail.gmail.com Link: https://lore.kernel.org/all/CAEAjamu1FRhz6StCe_55XY5s389ZP_xmCF69k987En+1z53=eg@mail.gmail.com Reported-by: Minh Yuan <yuanmingbuaa@gmail.com> Reported-by: syzbot+8e8958586909d62b6840@syzkaller.appspotmail.com Reported-by: cruise k <cruise4k@gmail.com> Reported-by: Kyungtae Kim <kt0755@gmail.com> Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Tested-by: Denis Efremov <efremov@linux.com> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.