23a6dfa10f
commit 80f6e3080bfcf865062a926817b3ca6c4a137a57 upstream. If the file size is almost S64_MAX, the calculated number of Merkle tree levels exceeds FS_VERITY_MAX_LEVELS, causing FS_IOC_ENABLE_VERITY to fail. This is unintentional, since as the comment above the definition of FS_VERITY_MAX_LEVELS states, it is enough for over U64_MAX bytes of data using SHA-256 and 4K blocks. (Specifically, 4096*128**8 >= 2**64.) The bug is actually that when the number of blocks in the first level is calculated from i_size, there is a signed integer overflow due to i_size being signed. Fix this by treating i_size as unsigned. This was found by the new test "generic: test fs-verity EFBIG scenarios" (https://lkml.kernel.org/r/b1d116cd4d0ea74b9cd86f349c672021e005a75c.1631558495.git.boris@bur.io). This didn't affect ext4 or f2fs since those have a smaller maximum file size, but it did affect btrfs which allows files up to S64_MAX bytes. Reported-by: Boris Burkov <boris@bur.io> Fixes: 3fda4c617e84 ("fs-verity: implement FS_IOC_ENABLE_VERITY ioctl") Fixes: fd2d1acfcadf ("fs-verity: add the hook for file ->open()") Cc: <stable@vger.kernel.org> # v5.4+ Reviewed-by: Boris Burkov <boris@bur.io> Link: https://lore.kernel.org/r/20210916203424.113376-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.