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authorAlexander Popov <alex.popov@linux.com>2020-01-03 02:49:07 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-02-10 13:43:38 -0800
commit01c0514ec8226386ce8367dcd8814f86224caaeb (patch)
treec2d7ab6f7b66dff0606e558e241b6cedf8ce86ab /drivers/misc/lkdtm
parentff5cd9accbc724a793904c6e401040c85be89748 (diff)
lkdtm/stackleak: Make the test more verbose
Make the stack erasing test more verbose about the errors that it can detect. Signed-off-by: Alexander Popov <alex.popov@linux.com> Cc: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20200102234907.585508-1-alex.popov@linux.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/lkdtm')
-rw-r--r--drivers/misc/lkdtm/stackleak.c25
1 files changed, 17 insertions, 8 deletions
diff --git a/drivers/misc/lkdtm/stackleak.c b/drivers/misc/lkdtm/stackleak.c
index d5a084475abc..d1a5c0705be3 100644
--- a/drivers/misc/lkdtm/stackleak.c
+++ b/drivers/misc/lkdtm/stackleak.c
@@ -16,6 +16,7 @@ void lkdtm_STACKLEAK_ERASING(void)
unsigned long *sp, left, found, i;
const unsigned long check_depth =
STACKLEAK_SEARCH_DEPTH / sizeof(unsigned long);
+ bool test_failed = false;
/*
* For the details about the alignment of the poison values, see
@@ -34,7 +35,8 @@ void lkdtm_STACKLEAK_ERASING(void)
left--;
} else {
pr_err("FAIL: not enough stack space for the test\n");
- return;
+ test_failed = true;
+ goto end;
}
pr_info("checking unused part of the thread stack (%lu bytes)...\n",
@@ -52,22 +54,29 @@ void lkdtm_STACKLEAK_ERASING(void)
}
if (found <= check_depth) {
- pr_err("FAIL: thread stack is not erased (checked %lu bytes)\n",
+ pr_err("FAIL: the erased part is not found (checked %lu bytes)\n",
i * sizeof(unsigned long));
- return;
+ test_failed = true;
+ goto end;
}
- pr_info("first %lu bytes are unpoisoned\n",
+ pr_info("the erased part begins after %lu not poisoned bytes\n",
(i - found) * sizeof(unsigned long));
/* The rest of thread stack should be erased */
for (; i < left; i++) {
if (*(sp - i) != STACKLEAK_POISON) {
- pr_err("FAIL: thread stack is NOT properly erased\n");
- return;
+ pr_err("FAIL: bad value number %lu in the erased part: 0x%lx\n",
+ i, *(sp - i));
+ test_failed = true;
}
}
- pr_info("OK: the rest of the thread stack is properly erased\n");
- return;
+end:
+ if (test_failed) {
+ pr_err("FAIL: the thread stack is NOT properly erased\n");
+ dump_stack();
+ } else {
+ pr_info("OK: the rest of the thread stack is properly erased\n");
+ }
}