From 2852ca7fba9f77b204f0fe953b31fadd0057c936 Mon Sep 17 00:00:00 2001 From: David Gow Date: Fri, 1 Jul 2022 16:47:41 +0800 Subject: [PATCH] panic: Taint kernel if tests are run Most in-kernel tests (such as KUnit tests) are not supposed to run on production systems: they may do deliberately illegal things to trigger errors, and have security implications (for example, KUnit assertions will often deliberately leak kernel addresses). Add a new taint type, TAINT_TEST to signal that a test has been run. This will be printed as 'N' (originally for kuNit, as every other sensible letter was taken.) This should discourage people from running these tests on production systems, and to make it easier to tell if tests have been run accidentally (by loading the wrong configuration, etc.) Acked-by: Luis Chamberlain Reviewed-by: Brendan Higgins Signed-off-by: David Gow Signed-off-by: Shuah Khan --- Documentation/admin-guide/tainted-kernels.rst | 1 + include/linux/panic.h | 3 ++- kernel/panic.c | 1 + 3 files changed, 4 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/tainted-kernels.rst b/Documentation/admin-guide/tainted-kernels.rst index ceeed7b0798d..7d80e8c307d1 100644 --- a/Documentation/admin-guide/tainted-kernels.rst +++ b/Documentation/admin-guide/tainted-kernels.rst @@ -100,6 +100,7 @@ Bit Log Number Reason that got the kernel tainted 15 _/K 32768 kernel has been live patched 16 _/X 65536 auxiliary taint, defined for and used by distros 17 _/T 131072 kernel was built with the struct randomization plugin + 18 _/N 262144 an in-kernel test has been run === === ====== ======================================================== Note: The character ``_`` is representing a blank in this table to make reading diff --git a/include/linux/panic.h b/include/linux/panic.h index e71161da69c4..c7759b3f2045 100644 --- a/include/linux/panic.h +++ b/include/linux/panic.h @@ -68,7 +68,8 @@ static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) #define TAINT_LIVEPATCH 15 #define TAINT_AUX 16 #define TAINT_RANDSTRUCT 17 -#define TAINT_FLAGS_COUNT 18 +#define TAINT_TEST 18 +#define TAINT_FLAGS_COUNT 19 #define TAINT_FLAGS_MAX ((1UL << TAINT_FLAGS_COUNT) - 1) struct taint_flag { diff --git a/kernel/panic.c b/kernel/panic.c index a3c758dba15a..6b3369e21026 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -428,6 +428,7 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { [ TAINT_LIVEPATCH ] = { 'K', ' ', true }, [ TAINT_AUX ] = { 'X', ' ', true }, [ TAINT_RANDSTRUCT ] = { 'T', ' ', true }, + [ TAINT_TEST ] = { 'N', ' ', true }, }; /**