From: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
[ Upstream commit 8bfdbddd68249e0d8598777cca8249619ee51df0 ]
When you don't select CONFIG_UBSAN_TRAP, you get:
# echo ARRAY_BOUNDS > /sys/kernel/debug/provoke-crash/DIRECT
[ 102.265827] ================================================================================
[ 102.278433] UBSAN: array-index-out-of-bounds in drivers/misc/lkdtm/bugs.c:342:16
[ 102.287207] index 8 is out of range for type 'char [8]'
[ 102.298722] ================================================================================
[ 102.313712] lkdtm: FAIL: survived array bounds overflow!
[ 102.318770] lkdtm: Unexpected! This kernel (5.16.0-rc1-s3k-dev-01884-g720dcf79314a ppc) was built with CONFIG_UBSAN_BOUNDS=y
It is not correct because when CONFIG_UBSAN_TRAP is not selected
you can't expect array bounds overflow to kill the thread.
Modify the logic so that when the kernel is built with
CONFIG_UBSAN_BOUNDS but without CONFIG_UBSAN_TRAP, you get a warning
about CONFIG_UBSAN_TRAP not been selected instead.
This also require a fix of pr_expected_config(), otherwise the
following error is encountered.
CC drivers/misc/lkdtm/bugs.o
drivers/misc/lkdtm/bugs.c: In function 'lkdtm_ARRAY_BOUNDS':
drivers/misc/lkdtm/bugs.c:351:2: error: 'else' without a previous 'if'
351 | else
| ^~~~
Fixes: c75be56e35b2 ("lkdtm/bugs: Add ARRAY_BOUNDS to selftests")
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/363b58690e907c677252467a94fe49444c80ea76.1649704381.git.christophe.leroy@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/misc/lkdtm/bugs.c | 5 ++++-
drivers/misc/lkdtm/lkdtm.h | 8 ++++----
2 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
index 072e3b742edf..fac4a811b97b 100644
--- a/drivers/misc/lkdtm/bugs.c
+++ b/drivers/misc/lkdtm/bugs.c
@@ -272,7 +272,10 @@ void lkdtm_ARRAY_BOUNDS(void)
kfree(not_checked);
kfree(checked);
pr_err("FAIL: survived array bounds overflow!\n");
- pr_expected_config(CONFIG_UBSAN_BOUNDS);
+ if (IS_ENABLED(CONFIG_UBSAN_BOUNDS))
+ pr_expected_config(CONFIG_UBSAN_TRAP);
+ else
+ pr_expected_config(CONFIG_UBSAN_BOUNDS);
}
void lkdtm_CORRUPT_LIST_ADD(void)
diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h
index c212a253edde..ef9a24aabfc3 100644
--- a/drivers/misc/lkdtm/lkdtm.h
+++ b/drivers/misc/lkdtm/lkdtm.h
@@ -9,19 +9,19 @@
extern char *lkdtm_kernel_info;
#define pr_expected_config(kconfig) \
-{ \
+do { \
if (IS_ENABLED(kconfig)) \
pr_err("Unexpected! This %s was built with " #kconfig "=y\n", \
lkdtm_kernel_info); \
else \
pr_warn("This is probably expected, since this %s was built *without* " #kconfig "=y\n", \
lkdtm_kernel_info); \
-}
+} while (0)
#ifndef MODULE
int lkdtm_check_bool_cmdline(const char *param);
#define pr_expected_config_param(kconfig, param) \
-{ \
+do { \
if (IS_ENABLED(kconfig)) { \
switch (lkdtm_check_bool_cmdline(param)) { \
case 0: \
@@ -52,7 +52,7 @@ int lkdtm_check_bool_cmdline(const char *param);
break; \
} \
} \
-}
+} while (0)
#else
#define pr_expected_config_param(kconfig, param) pr_expected_config(kconfig)
#endif
--
2.35.1
