With commit 16f196874 (kern/file: Implement filesystem reference
counting) files hold a reference to their file systems.
When closing a file in grub_file_close() we should not expect
file->fs to stay valid after calling grub_dl_unref() on file->fs->mod.
So, grub_dl_unref() should be called after file->fs->fs_close().
Fixes: CVE-2025-54771
Fixes: 16f196874 (kern/file: Implement filesystem reference counting)
Reported-by: Thomas Frauendorfer | Miray Software <tf@miray.de>
Signed-off-by: Thomas Frauendorfer | Miray Software <tf@miray.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The grub_file_open() and grub_file_close() should be the only places
that allow a reference to a filesystem to stay open. So, add grub_dl_t
to grub_fs_t and set this in the GRUB_MOD_INIT() for each filesystem to
avoid issues when filesystems forget to do it themselves or do not track
their own references, e.g. squash4.
The fs_label(), fs_uuid(), fs_mtime() and fs_read() should all ref and
unref in the same function but it is essentially redundant in GRUB
single threaded model.
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This is to avoid a generic issue were some filesystems would not set
data and also not set a grub_errno. This meant it was possible for many
filesystems to grub_dl_unref() themselves multiple times resulting in
it being possible to unload the filesystems while there were still
references to them, e.g., via a loopback.
Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
grub_file_open() calls grub_file_get_device_name(), but doesn't check
the return. Instead, it checks if grub_errno is set.
However, nothing initialises grub_errno here when grub_file_open()
starts. This means that trying to open one file that doesn't exist and
then trying to open another file that does will (incorrectly) also
fail to open that second file.
Let's fix that.
Signed-off-by: Steve McIntyre <steve@einval.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
If we have an error in grub_file_open() before we free device_name, we
will leak it.
Free device_name in the error path and null out the pointer in the good
path once we free it there.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Let's provide file type info to the I/O layer. This way verifiers
framework and its users will be able to differentiate files and verify
only required ones.
This is preparatory patch.
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
It cannot work anyway because host disk cannot be read. This fixes hostfs access
on native Windows build where filenames start with '\' or do not have initial
separator at all (d:\foo).
Issue was observed when running grub-fstest on Windows. On UNIX image name is
canonicalized to always start with `/' so this was not noticed.
This has side effect of allowing relative path names on host, but this already
was the case with `ls' command, so it just extends it to all commands.
Reported-By: Arch Stack <archstacker@gmail.com>
Also-By: Arch Stack <archstacker@gmail.com>
