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authorAndrey Konovalov <andreyknvl@google.com>2022-03-24 18:13:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-24 19:06:50 -0700
commitc32caa267b927b744610f4214bfde7ce7d55df1c (patch)
tree4f4148b432a813efff987a18e3b4bbdbb66c844e /mm
parent80207910cd71b4e0e87140d165d82b5d3ff69e53 (diff)
downloadlinux-c32caa267b927b744610f4214bfde7ce7d55df1c.tar.bz2
kasan: disable LOCKDEP when printing reports
If LOCKDEP detects a bug while KASAN is printing a report and if panic_on_warn is set, KASAN will not be able to finish. Disable LOCKDEP while KASAN is printing a report. See https://bugzilla.kernel.org/show_bug.cgi?id=202115 for an example of the issue. Link: https://lkml.kernel.org/r/c48a2a3288200b07e1788b77365c2f02784cfeb4.1646237226.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/kasan/report.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index c9bfffe931b4..199d77cce21a 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -13,6 +13,7 @@
#include <linux/ftrace.h>
#include <linux/init.h>
#include <linux/kernel.h>
+#include <linux/lockdep.h>
#include <linux/mm.h>
#include <linux/printk.h>
#include <linux/sched.h>
@@ -148,6 +149,8 @@ static void start_report(unsigned long *flags, bool sync)
disable_trace_on_warning();
/* Update status of the currently running KASAN test. */
update_kunit_status(sync);
+ /* Do not allow LOCKDEP mangling KASAN reports. */
+ lockdep_off();
/* Make sure we don't end up in loop. */
kasan_disable_current();
spin_lock_irqsave(&report_lock, *flags);
@@ -160,12 +163,13 @@ static void end_report(unsigned long *flags, void *addr)
trace_error_report_end(ERROR_DETECTOR_KASAN,
(unsigned long)addr);
pr_err("==================================================================\n");
- add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irqrestore(&report_lock, *flags);
if (panic_on_warn && !test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
panic("panic_on_warn set ...\n");
if (kasan_arg_fault == KASAN_ARG_FAULT_PANIC)
panic("kasan.fault=panic set ...\n");
+ add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
+ lockdep_on();
kasan_enable_current();
}