commit 4acfe3dfde upstream.
Dan Carpenter spotted a race condition in a couple of situations like
these in the test_firmware driver:
static int test_dev_config_update_u8(const char *buf, size_t size, u8 *cfg)
{
u8 val;
int ret;
ret = kstrtou8(buf, 10, &val);
if (ret)
return ret;
mutex_lock(&test_fw_mutex);
*(u8 *)cfg = val;
mutex_unlock(&test_fw_mutex);
/* Always return full write size even if we didn't consume all */
return size;
}
static ssize_t config_num_requests_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int rc;
mutex_lock(&test_fw_mutex);
if (test_fw_config->reqs) {
pr_err("Must call release_all_firmware prior to changing config\n");
rc = -EINVAL;
mutex_unlock(&test_fw_mutex);
goto out;
}
mutex_unlock(&test_fw_mutex);
rc = test_dev_config_update_u8(buf, count,
&test_fw_config->num_requests);
out:
return rc;
}
static ssize_t config_read_fw_idx_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
return test_dev_config_update_u8(buf, count,
&test_fw_config->read_fw_idx);
}
The function test_dev_config_update_u8() is called from both the locked
and the unlocked context, function config_num_requests_store() and
config_read_fw_idx_store() which can both be called asynchronously as
they are driver's methods, while test_dev_config_update_u8() and siblings
change their argument pointed to by u8 *cfg or similar pointer.
To avoid deadlock on test_fw_mutex, the lock is dropped before calling
test_dev_config_update_u8() and re-acquired within test_dev_config_update_u8()
itself, but alas this creates a race condition.
Having two locks wouldn't assure a race-proof mutual exclusion.
This situation is best avoided by the introduction of a new, unlocked
function __test_dev_config_update_u8() which can be called from the locked
context and reducing test_dev_config_update_u8() to:
static int test_dev_config_update_u8(const char *buf, size_t size, u8 *cfg)
{
int ret;
mutex_lock(&test_fw_mutex);
ret = __test_dev_config_update_u8(buf, size, cfg);
mutex_unlock(&test_fw_mutex);
return ret;
}
doing the locking and calling the unlocked primitive, which enables both
locked and unlocked versions without duplication of code.
The similar approach was applied to all functions called from the locked
and the unlocked context, which safely mitigates both deadlocks and race
conditions in the driver.
__test_dev_config_update_bool(), __test_dev_config_update_u8() and
__test_dev_config_update_size_t() unlocked versions of the functions
were introduced to be called from the locked contexts as a workaround
without releasing the main driver's lock and thereof causing a race
condition.
The test_dev_config_update_bool(), test_dev_config_update_u8() and
test_dev_config_update_size_t() locked versions of the functions
are being called from driver methods without the unnecessary multiplying
of the locking and unlocking code for each method, and complicating
the code with saving of the return value across lock.
Fixes: 7feebfa487 ("test_firmware: add support for request_firmware_into_buf")
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russ Weight <russell.h.weight@intel.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Tianfei Zhang <tianfei.zhang@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-kselftest@vger.kernel.org
Cc: stable@vger.kernel.org # v5.4
Suggested-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Link: https://lore.kernel.org/r/20230509084746.48259-1-mirsad.todorovac@alu.unizg.hr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7dae593cd2 upstream.
In a couple of situations like
name = kstrndup(buf, count, GFP_KERNEL);
if (!name)
return -ENOSPC;
the error is not actually "No space left on device", but "Out of memory".
It is semantically correct to return -ENOMEM in all failed kstrndup()
and kzalloc() cases in this driver, as it is not a problem with disk
space, but with kernel memory allocator failing allocation.
The semantically correct should be:
name = kstrndup(buf, count, GFP_KERNEL);
if (!name)
return -ENOMEM;
Cc: Dan Carpenter <error27@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Luis R. Rodriguez" <mcgrof@ruslug.rutgers.edu>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Brian Norris <briannorris@chromium.org>
Fixes: c92316bf8e ("test_firmware: add batched firmware tests")
Fixes: 0a8adf5847 ("test: add firmware_class loader test")
Fixes: 548193cba2 ("test_firmware: add support for firmware_request_platform")
Fixes: eb910947c8 ("test: firmware_class: add asynchronous request trigger")
Fixes: 061132d2b9 ("test_firmware: add test custom fallback trigger")
Fixes: 7feebfa487 ("test_firmware: add support for request_firmware_into_buf")
Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Message-ID: <20230606070808.9300-1-mirsad.todorovac@alu.unizg.hr>
Signed-off-by: Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit be37bed754 upstream.
Dan Carpenter spotted that test_fw_config->reqs will be leaked if
trigger_batched_requests_store() is called two or more times.
The same appears with trigger_batched_requests_async_store().
This bug wasn't trigger by the tests, but observed by Dan's visual
inspection of the code.
The recommended workaround was to return -EBUSY if test_fw_config->reqs
is already allocated.
Fixes: 7feebfa487 ("test_firmware: add support for request_firmware_into_buf")
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russ Weight <russell.h.weight@intel.com>
Cc: Tianfei Zhang <tianfei.zhang@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-kselftest@vger.kernel.org
Cc: stable@vger.kernel.org # v5.4
Suggested-by: Dan Carpenter <error27@gmail.com>
Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20230509084746.48259-2-mirsad.todorovac@alu.unizg.hr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d4fddac5a5 ]
In test_firmware_init(), the buffer pointed to by the global pointer
'test_fw_config' is allocated through kzalloc(). Then, the buffer is
initialized in __test_firmware_config_init(). In the case that the
initialization fails, the following execution in test_firmware_init() needs
to be terminated with an error code returned to indicate this failure.
However, the allocated buffer is not freed on this execution path, leading
to a memory leak bug.
To fix the above issue, free the allocated buffer before returning from
test_firmware_init().
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Link: https://lore.kernel.org/r/1563084696-6865-1-git-send-email-wang6495@umn.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit bd17cc5a20 upstream.
The limit here is supposed to be how much of the page is left, but it's
just using PAGE_SIZE as the limit.
The other thing to remember is that snprintf() returns the number of
bytes which would have been copied if we had had enough room. So that
means that if we run out of space then this code would end up passing a
negative value as the limit and the kernel would print an error message.
I have change the code to use scnprintf() which returns the number of
bytes that were successfully printed (not counting the NUL terminator).
Fixes: c92316bf8e ("test_firmware: add batched firmware tests")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 8bb0a88600 ]
In the case where eq->fw->size > PAGE_SIZE the error return rc
is being set to EINVAL however this is being overwritten to
rc = req->fw->size because the error exit path via label 'out' is
not being taken. Fix this by adding the jump to the error exit
path 'out'.
Detected by CoverityScan, CID#1453465 ("Unused value")
Fixes: c92316bf8e ("test_firmware: add batched firmware tests")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
The firmware API has a feature to enable batching requests for the same fil
e under one worker, so only one lookup is done. This only triggers if we so
happen to schedule two lookups for same file around the same time, or if
release_firmware() has not been called for a successful firmware call. This
can happen for instance if you happen to have multiple devices and one
device driver for certain drivers where the stars line up scheduling
wise.
This adds a new sync and async test trigger. Instead of adding a new
trigger for each new test type we make the tests a bit configurable so that
we could configure the tests in userspace and just kick a test through a
few basic triggers. With this, for instance the two types of sync requests:
o request_firmware() and
o request_firmware_direct()
can be modified with a knob. Likewise the two type of async requests:
o request_firmware_nowait(uevent=true) and
o request_firmware_nowait(uevent=false)
can be configured with another knob. The call request_firmware_into_buf()
has no users... yet.
The old tests are left in place as-is given they serve a few other purposes
which we are currently not interested in also testing yet. This will change
later as we will be able to just consolidate all tests under a few basic
triggers with just one general configuration setup.
We perform two types of tests, one for where the file is present and one
for where the file is not present. All test tests go tested and they now
pass for the following 3 kernel builds possible for the firmware API:
0. Most distro setup:
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n
CONFIG_FW_LOADER_USER_HELPER=y
1. Android:
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y
CONFIG_FW_LOADER_USER_HELPER=y
2. Rare build:
CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n
CONFIG_FW_LOADER_USER_HELPER=n
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We have no custom fallback mechanism test interface. Provide one.
This tests both the custom fallback mechanism and cancelling the
it.
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This will make further changes easier to review.
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We might want to test for bugs like that found in commit f9692b2699
("firmware: fix possible use after free on name on asynchronous
request"), where the asynchronous request API had race conditions.
Let's add a simple file that will launch the async request, then wait
until it's complete and report the status. It's not a true async test
(we're using a mutex + wait_for_completion(), so we can't get more than
one going at the same time), but it does help make sure the basic API is
sane, and it can catch some class of bugs.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
We're essentially just doing an open-coded kstrndup(). The only
differences are with what happens after the first '\0' character, but
request_firmware() doesn't care about that.
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
request_firmware() failures currently won't get reported at all (the
error code is discarded). What's more, we get confusing messages, like:
# echo -n notafile > /sys/devices/virtual/misc/test_firmware/trigger_request
[ 8280.311856] test_firmware: loading 'notafile'
[ 8280.317042] test_firmware: load of 'notafile' failed: -2
[ 8280.322445] test_firmware: loaded: 0
# echo $?
0
Report the failures via write() errors, and don't say we "loaded"
anything.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
This provides a simple interface to trigger the firmware_class loader
to test built-in, filesystem, and user helper modes. Additionally adds
tests via the new interface to the selftests tree.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mirsad Goran Todorovac