diff options
| author |   Alexander Popov <alex.popov@linux.com> | 2020-01-03 02:49:07 +0300 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-10 13:43:38 -0800 |
| commit | 01c0514ec8226386ce8367dcd8814f86224caaeb (patch) | |
| tree | c2d7ab6f7b66dff0606e558e241b6cedf8ce86ab /drivers/misc/lkdtm | |
| parent | ver_linux: Query ld cache for versions of libc/libcpp run-time (diff) | |
| download | wireguard-linux-01c0514ec8226386ce8367dcd8814f86224caaeb.tar.xz wireguard-linux-01c0514ec8226386ce8367dcd8814f86224caaeb.zip | |
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.c | 25 |
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"); + } } |