[PATCH V2 09/10] kasan: Prevent deadlock in kasan reporting
From: Aneesh Kumar K.V <hidden>
Date: 2015-08-26 08:27:07
Also in:
lkml
Subsystem:
kasan, memory management, the rest · Maintainers:
Andrey Ryabinin, Andrew Morton, Linus Torvalds
We we end up calling kasan_report in real mode, our shadow mapping for even spinlock variable will show poisoned. This will result in us calling kasan_report_error with lock_report spin lock held. To prevent this disable kasan reporting when we are priting error w.r.t kasan. Signed-off-by: Aneesh Kumar K.V <redacted> --- mm/kasan/report.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 79fbc5d14bd2..82b41eb83e43 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c@@ -185,6 +185,10 @@ void kasan_report_error(struct kasan_access_info *info) { unsigned long flags; + /* + * Make sure we don't end up in loop. + */ + kasan_disable_current(); spin_lock_irqsave(&report_lock, flags); pr_err("=================================" "=================================\n");
@@ -194,12 +198,17 @@ void kasan_report_error(struct kasan_access_info *info) pr_err("=================================" "=================================\n"); spin_unlock_irqrestore(&report_lock, flags); + kasan_enable_current(); } void kasan_report_user_access(struct kasan_access_info *info) { unsigned long flags; + /* + * Make sure we don't end up in loop. + */ + kasan_disable_current(); spin_lock_irqsave(&report_lock, flags); pr_err("=================================" "=================================\n");
@@ -212,6 +221,7 @@ void kasan_report_user_access(struct kasan_access_info *info) pr_err("=================================" "=================================\n"); spin_unlock_irqrestore(&report_lock, flags); + kasan_enable_current(); } void kasan_report(unsigned long addr, size_t size,
--
2.5.0