9ba55543fc
If user specify a large enough value of "commit=" option, it may trigger signed integer overflow which may lead to sbi->s_commit_interval becomes a large or small value, zero in particular. UBSAN: Undefined behaviour in ../fs/ext4/super.c:1592:31 signed integer overflow: 536870912 * 1000 cannot be represented in type 'int' [...] Call trace: [...] [<ffffff9008a2d120>] ubsan_epilogue+0x34/0x9c lib/ubsan.c:166 [<ffffff9008a2d8b8>] handle_overflow+0x228/0x280 lib/ubsan.c:197 [<ffffff9008a2d95c>] __ubsan_handle_mul_overflow+0x4c/0x68 lib/ubsan.c:218 [<ffffff90086d070c>] handle_mount_opt fs/ext4/super.c:1592 [inline] [<ffffff90086d070c>] parse_options+0x1724/0x1a40 fs/ext4/super.c:1773 [<ffffff90086d51c4>] ext4_remount+0x2ec/0x14a0 fs/ext4/super.c:4834 [...] Although it is not a big deal, still silence the UBSAN by limit the input value. Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
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.