From cd94fbc2cafb61cc1394cdba3f92b99ce07b03ae Mon Sep 17 00:00:00 2001 From: Daniel Latypov Date: Fri, 1 Oct 2021 18:36:35 -0700 Subject: [PATCH] kunit: fix too small allocation when using suite-only kunit.filter_glob When a user filters by a suite and not a test, e.g. $ ./tools/testing/kunit/kunit.py run 'suite_name' it hits this code const int len = strlen(filter_glob); ... parsed->suite_glob = kmalloc(len, GFP_KERNEL); which fails to allocate space for the terminating NULL. Somehow, it seems like we can't easily reproduce this under UML, so the existing `parse_filter_test()` didn't catch this. Fix this by allocating `len + 1` and switch to kzalloc() just to be a bit more defensive. We're only going to run this code once per kernel boot, and it should never be very long. Also update the unit tests to be a bit more cautious. This bug showed up as a NULL pointer dereference here: > KUNIT_EXPECT_STREQ(test, (const char *)filtered.start[0][0]->name, "suite0"); `filtered.start[0][0]` was NULL, and `name` is at offset 0 in the struct, so `...->name` was also NULL. Fixes: 3b29021ddd10 ("kunit: tool: allow filtering test cases via glob") Reported-by: kernel test robot Signed-off-by: Daniel Latypov Reviewed-by: David Gow Acked-by: Brendan Higgins Signed-off-by: Shuah Khan --- lib/kunit/executor.c | 2 +- lib/kunit/executor_test.c | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c index bab3ab940acc..1d7fecd33261 100644 --- a/lib/kunit/executor.c +++ b/lib/kunit/executor.c @@ -33,7 +33,7 @@ static void kunit_parse_filter_glob(struct kunit_test_filter *parsed, const char *period = strchr(filter_glob, '.'); if (!period) { - parsed->suite_glob = kmalloc(len, GFP_KERNEL); + parsed->suite_glob = kzalloc(len + 1, GFP_KERNEL); parsed->test_glob = NULL; strcpy(parsed->suite_glob, filter_glob); return; diff --git a/lib/kunit/executor_test.c b/lib/kunit/executor_test.c index edbd8184dcd7..4ed57fd94e42 100644 --- a/lib/kunit/executor_test.c +++ b/lib/kunit/executor_test.c @@ -149,6 +149,7 @@ static void filter_suites_test(struct kunit *test) KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered.start); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered.start[0]); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered.start[0][0]); KUNIT_EXPECT_STREQ(test, (const char *)filtered.start[0][0]->name, "suite0"); }