From: Kees Cook <keescook@chromium.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>,
Dmitry Vyukov <dvyukov@google.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Elena Petrova <lenaptr@google.com>,
Andrey Konovalov <andreyknvl@google.com>,
Alexander Potapenko <glider@google.com>,
Dan Carpenter <dan.carpenter@oracle.com>,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
Arnd Bergmann <arnd@arndb.de>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
kernel-hardening@lists.openwall.com, syzkaller@googlegroups.com
Subject: [PATCH v5 5/6] kasan: Unset panic_on_warn before calling panic()
Date: Thu, 27 Feb 2020 11:35:15 -0800 [thread overview]
Message-ID: <20200227193516.32566-6-keescook@chromium.org> (raw)
In-Reply-To: <20200227193516.32566-1-keescook@chromium.org>
As done in the full WARN() handler, panic_on_warn needs to be cleared
before calling panic() to avoid recursive panics.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
---
mm/kasan/report.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 5ef9f24f566b..54bd98a1fc7b 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -92,8 +92,16 @@ static void end_report(unsigned long *flags)
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();
}
--
2.20.1
next prev parent reply other threads:[~2020-02-27 19:35 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-27 19:35 [PATCH v5 0/6] ubsan: Split out bounds checker Kees Cook
2020-02-27 19:35 ` [PATCH v5 1/6] ubsan: Add trap instrumentation option Kees Cook
2020-02-27 19:35 ` [PATCH v5 2/6] ubsan: Split "bounds" checker from other options Kees Cook
2020-02-27 19:35 ` [PATCH v5 3/6] lkdtm/bugs: Add arithmetic overflow and array bounds checks Kees Cook
2020-02-27 19:35 ` [PATCH v5 4/6] ubsan: Check panic_on_warn Kees Cook
2020-02-27 19:35 ` Kees Cook [this message]
2020-02-27 19:35 ` [PATCH v5 6/6] ubsan: Include bug type in report header Kees Cook
2020-02-28 12:45 ` Andrey Konovalov
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