The patch titled
Subject: kasan: unset panic_on_warn before calling panic()
has been added to the -mm tree. Its filename is
kasan-unset-panic_on_warn-before-calling-panic.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kasan-unset-panic_on_warn-before-calling-panic.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kasan-unset-panic_on_warn-before-calling-panic.patch
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The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: kasan: unset panic_on_warn before calling panic()
As done in the full WARN() handler, panic_on_warn needs to be cleared
before calling panic() to avoid recursive panics.
Link: http://lkml.kernel.org/r/20200227193516.32566-6-keescook@xxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: Elena Petrova <lenaptr@xxxxxxxxxx>
Cc: "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/report.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
--- a/mm/kasan/report.c~kasan-unset-panic_on_warn-before-calling-panic
+++ a/mm/kasan/report.c
@@ -92,8 +92,16 @@ static void end_report(unsigned long *fl
pr_err("==================================================================\n");
add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irqrestore(&report_lock, *flags);
- if (panic_on_warn)
+ if (panic_on_warn) {
+ /*
+ * This thread may hit another WARN() in the panic path.
+ * Resetting this prevents additional WARN() from panicking the
+ * system on this thread. Other threads are blocked by the
+ * panic_mutex in panic().
+ */
+ panic_on_warn = 0;
panic("panic_on_warn set ...\n");
+ }
kasan_enable_current();
}
_
Patches currently in -mm which might be from keescook@xxxxxxxxxxxx are
shmem-distribute-switch-variables-for-initialization.patch
lib-test_stackinitc-xfail-switch-variable-init-tests.patch
ubsan-add-trap-instrumentation-option.patch
ubsan-split-bounds-checker-from-other-options.patch
lkdtm-bugs-add-arithmetic-overflow-and-array-bounds-checks.patch
ubsan-check-panic_on_warn.patch
kasan-unset-panic_on_warn-before-calling-panic.patch
ubsan-include-bug-type-in-report-header.patch
