From: Tingmao Wang Date: Sun, 15 Jun 2025 16:09:36 +0000 (+0100) Subject: landlock: Fix warning from KUnit tests X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e0a69cf2c03e61bd8069becb97f66c173d0d1fa1;p=thirdparty%2Fkernel%2Flinux.git landlock: Fix warning from KUnit tests get_id_range() expects a positive value as first argument but get_random_u8() can return 0. 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 constants, but max() 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 Link: https://lore.kernel.org/r/73e28efc5b8cc394608b99d5bc2596ca917d7c4a.1750003733.git.m@maowtm.org [mic: Minor cosmetic improvements] Signed-off-by: Mickaël Salaün --- diff --git a/security/landlock/id.c b/security/landlock/id.c index 56f7cc0fc7440..838c3ed7bb822 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 */