The kernel has only two users of proc_do_large_bitmap(), the kernel CPU
watchdog, and the ip_local_reserved_ports. Refer to watchdog_cpumask
and ip_local_reserved_ports in Documentation for further details on
these. When you input a large buffer into these, when it is larger than
PAGE_SIZE- 1, the input data gets misparsed, and the user get
incorrectly informed that the desired input value was set. This commit
implements a test which mimics and exploits that use case, it uses a
bitmap size, as in the watchdog case. The bitmap is used to test the
bitmap proc handler, proc_do_large_bitmap().
The next commit fixes this issue.
[akpm@linux-foundation.org: move proc_do_large_bitmap() export to EOF]
[mcgrof@kernel.org: use new target description for backward compatibility]
[mcgrof@kernel.org: augment test number to 50, ran into issues with bash string comparisons when testing up to 50 cases.]
[mcgrof@kernel.org: introduce and use verify_diff_proc_file() to use diff]
[mcgrof@kernel.org: use mktemp for tmp file]
[mcgrof@kernel.org: merge shell test and C code]
[mcgrof@kernel.org: commit log love]
[mcgrof@kernel.org: export proc_do_large_bitmap() to allow for the test
[mcgrof@kernel.org: check for the return value when writing to the proc file]
Link: http://lkml.kernel.org/r/20190320222831.8243-6-mcgrof@kernel.org
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On old kernels older new test knobs implemented on the test_sysctl
module may not be available. This is expected, and the selftests test
scripts should be able to run without failures on older kernels.
Generalize a solution so that we test for each required test target file
for each test by requiring each test description to annotate their
respective test target file. If the target file does not exist, we skip
the test gracefully.
Link: http://lkml.kernel.org/r/20190320222831.8243-5-mcgrof@kernel.org
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When verify_diff_w() is used we care about the result, not the verbose
output, and although we use -q, that still gives us a chatty message
about if the files differ or not. Since verify_diff_w() uses stdinput
the chatty message says whether or not "-" matches the target file, and
this just seems rather odd. Better to just ignore that messsage all
together, what we really care about i sthe results, the return value and
we check for that.
Link: http://lkml.kernel.org/r/20190320222831.8243-4-mcgrof@kernel.org
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently the test script checks for the existence of the sysctl test
module's directory path prior to loading it. We must first try to load
the module prior to checking for that path. This fixes the order for
the load / test.
Link: http://lkml.kernel.org/r/20190320222831.8243-3-mcgrof@kernel.org
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "sysctl: add pending proc_do_large_bitmap fix".
Eric sent a fix out for proc_do_large_bitmap() last month for when using
a large input buffer. After patch review a test case for the issue was
built and submitted. I noticed there were a few issues with the tests,
but instead of just asking Eric to address them I've taken care of them
and ammended the commit where necessary. There's a few issues he
reported which I also address and fix in this series.
Since we *do* expect users of these scripts to also use them on older
kernels, I've also addressed not breaking calling the script for them,
and gives us an easy way to easily extend our tests cases for future
kernels as well.
Before anyone considers these for stable as minor fixes, I'd recommend
we also address the discrepancy on the read side of things: modify the
test script to use diff against the target file instead of using the
temp file.
This patch (of 6):
We already call test_reqs(), no need to call it twice.
Link: http://lkml.kernel.org/r/20190320222831.8243-2-mcgrof@kernel.org
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "sysctl: fix range-checking in do_proc_dointvec_minmax_conv()", v2.
After being left with an unusable system after a typo executing
something like 'echo $((1<<24)) > /proc/sys/vm/max_map_count', I found
that do_proc_dointvec_minmax_conv() was missing a check to ensure that
the converted value actually fits in an int.
The first of the following patches enhances the sysctl selftest such
that it detects this problem; the second provides a minimal fix
(suitable for -stable) such that the selftest passes. The third patch
then performs a more thorough refactoring to eliminate the code
duplication that led to the bug in the first place (maintaining the
passing status of the selftest).
This patch (of 3):
At present this exposes a bug in do_proc_dointvec_minmax_conv() (it
fails to check for values that are too wide to fit in an int).
Link: http://lkml.kernel.org/r/20190207123426.9202-2-zev@bewilderbeest.net
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When sysctl test is skipped because of unmet dependencies and/or
unsupported configuration, it exits with error which is treated as
a fail by the Kselftest framework. This leads to false negative result
even when the test could not be run.
Change it to return kselftest skip code when a test gets skipped to
clearly report that the test could not be run.
Changed return code to kselftest skip code in skip error legs that check
requirements and module probe test error leg.
Kselftest framework SKIP code is 4 and the framework prints appropriate
messages to indicate that the test is skipped.
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
We had just forogtten to do this. Without this the following test fails:
$ sudo make -C tools/testing/selftests/sysctl/ run_tests
make: Entering directory '/home/mcgrof/linux-next/tools/testing/selftests/sysctl'
/bin/sh: ./sysctl.sh: Permission denied
selftests: sysctl.sh [FAIL]
/home/mcgrof/linux-next/tools/testing/selftests/sysctl
make: Leaving directory '/home/mcgrof/linux-next/tools/testing/selftests/sysctl'
Fixes: 64b671204a ("test_sysctl: add generic script to expand on tests")
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Add a few initial respective tests for an array:
o Echoing values separated by spaces works
o Echoing only first elements will set first elements
o Confirm PAGE_SIZE limit still applies even if an array is used
Link: http://lkml.kernel.org/r/20170630224431.17374-7-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Test against a simple proc_douintvec() case. While at it, add a test
against UINT_MAX. Make sure UINT_MAX works, and UINT_MAX+1 will fail
and that negative values are not accepted.
Link: http://lkml.kernel.org/r/20170630224431.17374-6-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Test against a simple proc_dointvec() case. While at it, add a test
against INT_MAX. Make sure INT_MAX works, and INT_MAX+1 will fail.
Also test negative values work.
Link: http://lkml.kernel.org/r/20170630224431.17374-5-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add the following tests to ensure we do not regress:
o Test using a buffer full of space (PAGE_SIZE-1) followed by a
single digit works
o Test using a buffer full of spaces (PAGE_SIZE or over) will fail
As tests increase instead of unloading the module and reloading it we
can just do a shell reset_vals() with a reset to values we know are set
at init on the driver.
Link: http://lkml.kernel.org/r/20170630224431.17374-4-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds a generic script to let us more easily add more tests cases.
Since we really have only two types of tests cases just fold them into
the one file. Each test unit is now identified into its separate
function:
# ./sysctl.sh -l
Test ID list:
TEST_ID x NUM_TEST
TEST_ID: Test ID
NUM_TESTS: Number of recommended times to run the test
0001 x 1 - tests proc_dointvec_minmax()
0002 x 1 - tests proc_dostring()
For now we start off with what we had before, and run only each test
once. We can now watch a test case until it fails:
./sysctl.sh -w 0002
We can also run a test case x number of times, say we want to run a test
case 100 times:
./sysctl.sh -c 0001 100
To run a test case only once, for example:
./sysctl.sh -s 0002
The default settings are specified at the top of sysctl.sh.
Link: http://lkml.kernel.org/r/20170630224431.17374-3-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Eric Sandeen