In kunit_debugfs_create_suite() give up and skip creating the debugfs file if any of the alloc_string_stream() calls return an error or NULL. Only put a value in the log pointer of kunit_suite and kunit_test if it is a valid pointer to a log.

This prevents the potential invalid dereference reported by smatch:

lib/kunit/debugfs.c:115 kunit_debugfs_create_suite() error: 'suite->log' dereferencing possible ERR_PTR() lib/kunit/debugfs.c:119 kunit_debugfs_create_suite() error: 'test_case->log' dereferencing possible ERR_PTR()

Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com Reported-by: Dan Carpenter dan.carpenter@linaro.org Fixes: 05e2006ce493 ("kunit: Use string_stream for test log") Reviewed-by: Rae Moar rmoar@google.com --- Changes from V1: - If the alloc_string_stream() for the suite->log fails just return. Nothing has been created at this point so there's nothing to clean up. - Re-word the explanation of why the log pointers are only set if they point to a valid log.

As these changes are trivial I've carried Rae Moar's Reviewed-by from V1. --- lib/kunit/debugfs.c | 30 +++++++++++++++++++++++++----- 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c index 270d185737e6..9d167adfa746 100644 --- a/lib/kunit/debugfs.c +++ b/lib/kunit/debugfs.c @@ -109,14 +109,28 @@ static const struct file_operations debugfs_results_fops = { void kunit_debugfs_create_suite(struct kunit_suite *suite) { struct kunit_case *test_case; + struct string_stream *stream;

- /* Allocate logs before creating debugfs representation. */ - suite->log = alloc_string_stream(GFP_KERNEL); - string_stream_set_append_newlines(suite->log, true); + /* + * Allocate logs before creating debugfs representation. + * The suite->log and test_case->log pointer are expected to be NULL + * if there isn't a log, so only set it if the log stream was created + * successfully. + */ + stream = alloc_string_stream(GFP_KERNEL); + if (IS_ERR_OR_NULL(stream)) + return; + + string_stream_set_append_newlines(stream, true); + suite->log = stream;

kunit_suite_for_each_test_case(suite, test_case) { - test_case->log = alloc_string_stream(GFP_KERNEL); - string_stream_set_append_newlines(test_case->log, true); + stream = alloc_string_stream(GFP_KERNEL); + if (IS_ERR_OR_NULL(stream)) + goto err; + + string_stream_set_append_newlines(stream, true); + test_case->log = stream; }

suite->debugfs = debugfs_create_dir(suite->name, debugfs_rootdir); @@ -124,6 +138,12 @@ void kunit_debugfs_create_suite(struct kunit_suite *suite) debugfs_create_file(KUNIT_DEBUGFS_RESULTS, S_IFREG | 0444, suite->debugfs, suite, &debugfs_results_fops); + return; + +err: + string_stream_destroy(suite->log); + kunit_suite_for_each_test_case(suite, test_case) + string_stream_destroy(test_case->log); }

void kunit_debugfs_destroy_suite(struct kunit_suite *suite)