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| author | Andrey Konovalov <andreyknvl@google.com> | 2022-03-24 18:13:15 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-24 19:06:50 -0700 |
| commit | c32caa267b927b744610f4214bfde7ce7d55df1c (patch) | |
| tree | 4f4148b432a813efff987a18e3b4bbdbb66c844e /mm/kasan | |
| parent | 80207910cd71b4e0e87140d165d82b5d3ff69e53 (diff) | |
| download | lwn-c32caa267b927b744610f4214bfde7ce7d55df1c.tar.gz lwn-c32caa267b927b744610f4214bfde7ce7d55df1c.zip | |
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/kasan')
| -rw-r--r-- | mm/kasan/report.c | 6 |
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(); } |