97ee8505c6
[ Upstream commit 09a4e0be5826aa66c4ce9954841f110ffe63ef4f ]
The largest block size supported by isofs is ISOFS_BLOCK_SIZE (2048), but
isofs_fill_super calls sb_min_blocksize and sets the blocksize to the
device's logical block size if it's larger than what we ended up with after
option parsing.
If for some reason we try to mount a hard 4k device as an isofs filesystem,
we'll set opt.blocksize to 4096, and when we try to read the superblock
we found via:
block = iso_blknum << (ISOFS_BLOCK_BITS - s->s_blocksize_bits)
with s_blocksize_bits greater than ISOFS_BLOCK_BITS, we'll have a negative
shift and the bread will fail somewhat cryptically:
isofs_fill_super: bread failed, dev=sda, iso_blknum=17, block=-2147483648
It seems best to just catch and clearly reject mounts of such a device.
Reported-by: Bryan Gurney <bgurney@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.