[PATCH] landlock/id: Fix WARNING from kunit tests
Tingmao Wang
m at maowtm.org
Sun Jun 15 16:09:36 UTC 2025
Looks like get_random_u8 returned 0 here. Fix this by clamping it.
(Validated by running the test in a for loop for 1000 times. Note that
MAX is wrong as it is only supposed to be used for unchanging variables,
but the lowercase version is good here.)
[..] ok 9 test_range2_rand1
[..] ok 10 test_range2_rand2
[..] ok 11 test_range2_rand15
[..] ------------[ cut here ]------------
[..] WARNING: CPU: 6 PID: 104 at security/landlock/id.c:99 test_range2_rand16 (security/landlock/id.c:99 (discriminator 1) security/landlock/id.c:234 (discriminator 1))
[..] Modules linked in:
[..] CPU: 6 UID: 0 PID: 104 Comm: kunit_try_catch Tainted: G N 6.16.0-rc1-dev-00001-g314a2f98b65f #1 PREEMPT(undef)
[..] Tainted: [N]=TEST
[..] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[..] RIP: 0010:test_range2_rand16 (security/landlock/id.c:99 (discriminator 1) security/landlock/id.c:234 (discriminator 1))
[..] Code: 49 c7 c0 10 70 30 82 4c 89 ff 48 c7 c6 a0 63 1e 83 49 c7 45 a0 e0 63 1e 83 e8 3f 95 17 00 e9 1f ff ff ff 0f 0b e9 df fd ff ff <0f> 0b ba 01 00 00 00 e9 68 fe ff ff 49 89 45 a8 49 8d 4d a0 45 31
..
[..] RSP: 0000:ffff888104eb7c78 EFLAGS: 00010246
[..] RAX: 0000000000000000 RBX: 000000000870822c RCX: 0000000000000000
^^^^^^^^^^^^^^^^
[..]
[..] Call Trace:
[..]
[..] ---[ end trace 0000000000000000 ]---
[..] ok 12 test_range2_rand16
[..] # landlock_id: pass:12 fail:0 skip:0 total:12
[..] # Totals: pass:12 fail:0 skip:0 total:12
[..] ok 1 landlock_id
Fixes: d9d2a68ed44b ("landlock: Add unique ID generator")
Signed-off-by: Tingmao Wang <m at maowtm.org>
---
security/landlock/id.c | 69 +++++++++++++++++++++++++-----------------
1 file changed, 42 insertions(+), 27 deletions(-)
diff --git a/security/landlock/id.c b/security/landlock/id.c
index 56f7cc0fc744..b02a7da2f15d 100644
--- a/security/landlock/id.c
+++ b/security/landlock/id.c
@@ -119,6 +119,12 @@ static u64 get_id_range(size_t number_of_ids, atomic64_t *const counter,
#ifdef CONFIG_SECURITY_LANDLOCK_KUNIT_TEST
+static u8 get_random_u8_positive(void)
+{
+ /* max evaluates its arguments once */
+ return max(1, get_random_u8());
+}
+
static void test_range1_rand0(struct kunit *const test)
{
atomic64_t counter;
@@ -127,9 +133,10 @@ static void test_range1_rand0(struct kunit *const test)
init = get_random_u32();
atomic64_set(&counter, init);
KUNIT_EXPECT_EQ(test, get_id_range(1, &counter, 0), init);
- KUNIT_EXPECT_EQ(
- test, get_id_range(get_random_u8(), &counter, get_random_u8()),
- init + 1);
+ KUNIT_EXPECT_EQ(test,
+ get_id_range(get_random_u8_positive(), &counter,
+ get_random_u8()),
+ init + 1);
}
static void test_range1_rand1(struct kunit *const test)
@@ -140,9 +147,10 @@ static void test_range1_rand1(struct kunit *const test)
init = get_random_u32();
atomic64_set(&counter, init);
KUNIT_EXPECT_EQ(test, get_id_range(1, &counter, 1), init);
- KUNIT_EXPECT_EQ(
- test, get_id_range(get_random_u8(), &counter, get_random_u8()),
- init + 2);
+ KUNIT_EXPECT_EQ(test,
+ get_id_range(get_random_u8_positive(), &counter,
+ get_random_u8()),
+ init + 2);
}
static void test_range1_rand15(struct kunit *const test)
@@ -153,9 +161,10 @@ static void test_range1_rand15(struct kunit *const test)
init = get_random_u32();
atomic64_set(&counter, init);
KUNIT_EXPECT_EQ(test, get_id_range(1, &counter, 15), init);
- KUNIT_EXPECT_EQ(
- test, get_id_range(get_random_u8(), &counter, get_random_u8()),
- init + 16);
+ KUNIT_EXPECT_EQ(test,
+ get_id_range(get_random_u8_positive(), &counter,
+ get_random_u8()),
+ init + 16);
}
static void test_range1_rand16(struct kunit *const test)
@@ -166,9 +175,10 @@ static void test_range1_rand16(struct kunit *const test)
init = get_random_u32();
atomic64_set(&counter, init);
KUNIT_EXPECT_EQ(test, get_id_range(1, &counter, 16), init);
- KUNIT_EXPECT_EQ(
- test, get_id_range(get_random_u8(), &counter, get_random_u8()),
- init + 1);
+ KUNIT_EXPECT_EQ(test,
+ get_id_range(get_random_u8_positive(), &counter,
+ get_random_u8()),
+ init + 1);
}
static void test_range2_rand0(struct kunit *const test)
@@ -179,9 +189,10 @@ static void test_range2_rand0(struct kunit *const test)
init = get_random_u32();
atomic64_set(&counter, init);
KUNIT_EXPECT_EQ(test, get_id_range(2, &counter, 0), init);
- KUNIT_EXPECT_EQ(
- test, get_id_range(get_random_u8(), &counter, get_random_u8()),
- init + 2);
+ KUNIT_EXPECT_EQ(test,
+ get_id_range(get_random_u8_positive(), &counter,
+ get_random_u8()),
+ init + 2);
}
static void test_range2_rand1(struct kunit *const test)
@@ -192,9 +203,10 @@ static void test_range2_rand1(struct kunit *const test)
init = get_random_u32();
atomic64_set(&counter, init);
KUNIT_EXPECT_EQ(test, get_id_range(2, &counter, 1), init);
- KUNIT_EXPECT_EQ(
- test, get_id_range(get_random_u8(), &counter, get_random_u8()),
- init + 3);
+ KUNIT_EXPECT_EQ(test,
+ get_id_range(get_random_u8_positive(), &counter,
+ get_random_u8()),
+ init + 3);
}
static void test_range2_rand2(struct kunit *const test)
@@ -205,9 +217,10 @@ static void test_range2_rand2(struct kunit *const test)
init = get_random_u32();
atomic64_set(&counter, init);
KUNIT_EXPECT_EQ(test, get_id_range(2, &counter, 2), init);
- KUNIT_EXPECT_EQ(
- test, get_id_range(get_random_u8(), &counter, get_random_u8()),
- init + 4);
+ KUNIT_EXPECT_EQ(test,
+ get_id_range(get_random_u8_positive(), &counter,
+ get_random_u8()),
+ init + 4);
}
static void test_range2_rand15(struct kunit *const test)
@@ -218,9 +231,10 @@ static void test_range2_rand15(struct kunit *const test)
init = get_random_u32();
atomic64_set(&counter, init);
KUNIT_EXPECT_EQ(test, get_id_range(2, &counter, 15), init);
- KUNIT_EXPECT_EQ(
- test, get_id_range(get_random_u8(), &counter, get_random_u8()),
- init + 17);
+ KUNIT_EXPECT_EQ(test,
+ get_id_range(get_random_u8_positive(), &counter,
+ get_random_u8()),
+ init + 17);
}
static void test_range2_rand16(struct kunit *const test)
@@ -231,9 +245,10 @@ static void test_range2_rand16(struct kunit *const test)
init = get_random_u32();
atomic64_set(&counter, init);
KUNIT_EXPECT_EQ(test, get_id_range(2, &counter, 16), init);
- KUNIT_EXPECT_EQ(
- test, get_id_range(get_random_u8(), &counter, get_random_u8()),
- init + 2);
+ KUNIT_EXPECT_EQ(test,
+ get_id_range(get_random_u8_positive(), &counter,
+ get_random_u8()),
+ init + 2);
}
#endif /* CONFIG_SECURITY_LANDLOCK_KUNIT_TEST */
base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494
--
2.49.0
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